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We integrate a spatial light modulator-based dispersion controller into a cascaded four-wave mixing (CFWM) system. By tuning the group delay dispersion (GDD) and fourth-order dispersion (FOD) terms, we control the CFWM phase matching and demonstrate an output bandwidth tuning of over 3.3×. At the maximum bandwidth, our system covers the telecommunications S-, C-, and L-bands (1466-1641 nm) with an average output power of 300 mW, which is contained in 52 individual lines spaced 374 GHz apart. This method represents a reconfigurable alternative to photonic crystal fibers for dispersion engineering and allows for the use of step-index fiber and customizable power spectral density (PSD) profiles.
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INTRODUCTION: Acute kidney injury (AKI) requiring treatment with renal replacement therapy (RRT) is a common complication after admission to an intensive care unit (ICU) and is associated with significant morbidity and mortality. However, the prevalence of RRT use and the associated outcomes in critically patients across the globe are not well described. Therefore, we describe the epidemiology and outcomes of patients receiving RRT for AKI in ICUs across several large health system jurisdictions. METHODS: Retrospective cohort analysis using nationally representative and comparable databases from seven health jurisdictions in Australia, Brazil, Canada, Denmark, New Zealand, Scotland, and the USA between 2006 and 2023, depending on data availability of each dataset. Patients with a history of end-stage kidney disease receiving chronic RRT and patients with a history of renal transplant were excluded. RESULTS: A total of 4,104,480 patients in the ICU cohort and 3,520,516 patients in the mechanical ventilation cohort were included. Overall, 156,403 (3.8%) patients in the ICU cohort and 240,824 (6.8%) patients in the mechanical ventilation cohort were treated with RRT for AKI. In the ICU cohort, the proportion of patients treated with RRT was lowest in Australia and Brazil (3.3%) and highest in Scotland (9.2%). The in-hospital mortality for critically ill patients treated with RRT was almost fourfold higher (57.1%) than those not receiving RRT (16.8%). The mortality of patients treated with RRT varied across the health jurisdictions from 37 to 65%. CONCLUSION: The outcomes of patients who receive RRT in ICUs throughout the world vary widely. Our research suggests that differences in access to and provision of this therapy are contributing factors.
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A patient attended for an MRI scan wearing Heattech thermal clothing. Following the scan, the patient experienced a heating and sunburn sensation over their back. Further investigation has highlighted one similar event to this internationally due to the clothing technology used. The intention of this report is to raise awareness of the potential for this clothing technology to cause thermal injury when worn within MRI, as well as to further emphasise the importance of assessing patient clothing prior to scanning.
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Health information system implementations are expensive and risky. They have the potential to transform healthcare when implemented successfully. Health leaders need to effectively engage physicians as an important constituent in the project. This can be accomplished by applying user-centred design principles, facilitating physician leadership, and planning for training. When done effectively, a sense of shared ownership and allegiance between management and the physician group is created that will lead to a successful project.
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Sistemas de Informação em Saúde , Médicos , Humanos , Atenção à Saúde , LiderançaRESUMO
OBJECTIVES: This study's goal was to determine the perceived risks of infection as well as the perceived risks of hospitalization and death from COVID-19 in Ecuador and Kenya. It also assessed the factors associated with the risk-related perceptions. METHODS: Cross-sectional studies with samples from the adult populations in both countries were conducted to assess the perceived risks of contracting COVID-19. Data were collected online using the Qualtrics platform (Qualtrics, Provo, Utah, United States) from samples of 1050 heads of households, aged 18 years or older, in each country. A total of 3 statistical analyses were conducted: summary statistics, correlation, and linear regression. RESULTS: The average perceived risks of COVID-19 infection, hospitalization, and death in the Kenyan sample were 27.1%, 43.2%, and 17.2%, respectively, and the values for the Ecuadorian sample were 34%, 32.8%, and 23.3%, respectively. The Pearson's correlation coefficients between the risk measures in each country were less than 0.38. Risk measures were associated with several sociodemographic variables (e.g., income, gender, location), but not with age. CONCLUSIONS: The perceived risks of COVID-19 infection, hospitalization, and death in Kenya and Ecuador were significantly higher relative to the statistics reported; however, no strong association existed between perceived risk and age, which is a key factor in adverse health outcomes, including death, among COVID-19 infected individuals.
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The goal of achieving herd immunity to the coronavirus requires high vaccination acceptance levels on the part of the population. The objectives of this study were to: 1) Measure individuals' willingness to pay (WTP) for a COVID-19 vaccine in Kenya; 2) evaluate the effect of vaccine characteristics (duration of protection and efficacy) and individuals' socioeconomic variables on WTP, and 3) estimate the aggregate demand and economic value of a COVID-19 vaccine. The contingent valuation (CV) method was used as the basis for the analyses. Data for this study were obtained from a survey of 1,050 individuals in Kenya conducted from April 7 to April 15, 2020. The survey included CV questions using a double-bounded dichotomous choice format. Results reveal that most of the individuals in Kenya (at least 96%) were willing to accept a COVID-19 vaccine. Approximately 80% of individuals were willing to pay a positive amount. Conservative estimates of individuals' mean WTP for the vaccine range from USD 49.81 to USD 68.25 (depending on vaccine characteristics). Both vaccine duration of protection and efficacy were found to influence WTP (p < .10). The perceived probability of being hospitalized, age, gender, education, location and region of residence, and household income were also found to be associated with WTP for the vaccine (p < .10). In conclusion, the COVID-19 vaccine is highly valued and accepted by the Kenyan population; however, a high percent of the population is unwilling to pay for it or is only willing to pay a low price.
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COVID-19 , Vacinas , Vacinas contra COVID-19 , Humanos , Quênia , SARS-CoV-2RESUMO
INTRODUCTION: This Educational Perspective provides an overview of how leadership fits into advanced and consultant radiographic roles within the UK setting. It draws on research in the area as well as reviewing some of the wider healthcare literature beyond the medical radiation sciences. The reflections outlined suggest how leadership at these levels may look and differ in practice. DISCUSSION: Leadership should be seen as fundamental to practice and not necessarily a discreet element to either role, but one that supports all other areas. The proportion of the role that leadership takes up, along with the degree of influence, increases from advanced to consultant practice. Consideration over conflict with management and leadership within roles is also important. Ultimately leadership is about relationships with people, for which interpersonal skills are required, along with establishing networks, supported by training and development to maximise effectiveness. CONCLUSION: A clearer understanding of leadership is needed to help conceptualise and measure its impact at advanced and consultant levels of practice. The content is intended to provide an opportunity for reflection and discussion around the topic, serving as a development tool in practice.
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Consultores , Liderança , Atenção à Saúde , Humanos , Reino UnidoRESUMO
BACKGROUND: With an ongoing move towards more management of patients within the community setting, demand for magnetic resonance imaging (MRI) is increasing and commonly used in lower back conditions. There is well recorded overuse of MRI in this scenario which goes against evidence-based practice and adds to rising healthcare costs. METHODS: The study was a retrospective review of lumbar spine MRI scans performed within a community-based setting over an 18-month period. The review took a randomised purposive sample of patients (n = 450); looking at adherence to, and relevance of, guidelines in managing lower back conditions. Data extracted provided information on demographics and prevalence of clinical presentation and report observations. RESULTS: There is variation in practice and utlisation of MRI with this patient group which warrants further exploration. Results support inappropriate use, lacking adherence to guidelines and pathways, leading to unnecessary imaging. 46% of referrals were considered clinically justified with 38% of report findings considered abnormal and of clinical relevance. Chi-square and binomial logistic regression were used to assess the significance and relationship of any factors on referral justification and report outcome. No difference was found between type of referrer, with patient age and leg symptoms being significant factors. CONCLUSION: The study highlights the opportunity to integrate better referral criteria to improve referral quality, its suitability and the relevance of final reports. In the current climate this would help manage appropriate use of imaging resources during the post COVID-19 pandemic recovery phase, as well as support recommendations regarding diagnostic reform and a move towards more community-based diagnostics.
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Dor Lombar/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , COVID-19 , Inglaterra/epidemiologia , Feminino , Fidelidade a Diretrizes , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , SARS-CoV-2RESUMO
In Latin America, the country of Ecuador was one of the first and most severely affected by the COVID-19 pandemic. This study aimed to evaluate the demand for a COVID-19 vaccine in Ecuador by estimating individuals' willingness to pay (WTP) for the vaccine, and by assessing the effect of vaccine attributes (duration of protection and efficacy) and individuals' characteristics on this valuation. The sample used (N = 1,050) was obtained through an online survey conducted from April 2 to April 7, 2020. Two levels of vaccine efficacy (70% and 98%) and two levels of vaccine duration of protection (1 and 20 years) were considered. The willingness to pay estimates were obtained using a double-bounded dichotomous-choice contingent valuation format. Survey results show that a very large proportion of individuals (at least 97%) were willing to accept a COVID-19 vaccine, and at least 85% of individuals were willing to pay a positive amount for that vaccine. Conservative estimates of the average WTP values ranged from USD 147.61 to 196.65 and the median WTP from USD 76.9 to 102.5. Only the duration of protection was found to influence individuals' WTP for the vaccine (p < 0.01). On average, respondents were willing to pay 30% more for a COVID-19 vaccine with 20 years of protection relative to the vaccine with 1 year of protection. Regression results show that WTP for the vaccine was associated with income, employment status, the perceived probability of needing hospitalization if contracting the virus causing COVID-19, and region of residence.
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Vacinas contra COVID-19/economia , Vacinas contra COVID-19/imunologia , COVID-19/imunologia , Adulto , Equador , Feminino , Humanos , Masculino , Pandemias/economia , Pandemias/prevenção & controle , SARS-CoV-2/imunologia , Inquéritos e Questionários , Vacinação/economiaRESUMO
We study the propagation of ultrashort pulses in optical fiber with gain and positive (or normal) quartic dispersion by self-similarity analysis of the modified nonlinear Schrödinger equation. We find an exact asymptotic solution, corresponding to a triangle-like T4/3 intensity profile, with a T1/3 chirp, which is confirmed by numerical simulations. This solution follows different amplitude and width scaling compared to the conventional case with quadratic dispersion. We also suggest, and numerically investigate, a fiber laser consisting of components with positive quartic dispersion that emits quartic self-similar pulses.
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Venoarterial extracorporeal membrane oxygenation (VA-ECMO) can be an efficacious cardiopulmonary support for adults as rescue from refractory cardiogenic shock. It is best employed as a bridging strategy to recovery or alternative support rather than sustained, long-term mechanical circulatory support. The purpose of this paper is to discuss strategies to optimize patient management on VA-ECMO and approaches to promote successful separation from support. Rapid medical optimization will assist in reducing the time on VA-ECMO, thereby improving the likelihood of patient salvage. Suitably trained physicians and personnel, guided by structured protocols, can promote excellence in team care and provision of consistent management. Focusing on anticoagulation, careful neurologic monitoring, prevention of leg ischemia, awareness of differential hypoxemia, optimizing mechanical ventilation, identifying and timely intervention for left-ventricular distension (LVD), along with a strategic weaning algorithm, can prevent significant morbidity and mortality. LVD physiology, diagnosis, and risk factors are reviewed. Indications for LV decompression, along with medical and mechanical management options, are elucidated.
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Oxigenação por Membrana Extracorpórea , Choque Cardiogênico/terapia , Adulto , Artérias , Oxigenação por Membrana Extracorpórea/métodos , Humanos , VeiasRESUMO
Background: Pseudomonas aeruginosa (PA) infection in the intensive care unit (ICU) contributes to substantial mortality. In this study, we describe the epidemiology, antimicrobial susceptibilities, and outcomes of ICU patients with pseudomonal infection. Methods: ICU patients with PA were identified and classified as colonized or infected. Infected patients were reviewed for source, patient characteristics, antimicrobial susceptibilities, appropriateness of empiric antimicrobial therapy, and 30-day mortality. Independent predictors of mortality were identified using multivariable logistic regression. Results: One hundred forty (71%) patients with PA were infected. Mean patient age was 55 (SD 18) years; 62% were male. Admission categories included medical (71%), surgical (20%), and trauma or neurological (9%). Mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 19 (SD 10). One hundred twenty-six (90%) patients were mechanically ventilated, 102 (73%) required vasopressors, and 27 (19%) received renal replacement; 32 (23%) died within 30 days. Infection was nosocomial in 101 (72%) cases. Sources were respiratory (66%), skin-soft tissue (11%), urinary (10%), blood (5%), surgical (5%), gastrointestinal (2%), or unknown (1%). Twenty (14%) isolates were multi-drug resistant; 6 (4%) were extensively drug resistant. Empiric antimicrobial therapy was effective in 97 (69%) cases. Liver disease (adjusted OR [aOR] 6.2, 95% CI 1.5 to 25.7; p = 0.01), malignancy (aOR 5.0, 95% CI 1.5 to 17.3; p = 0.01), and higher APACHE II score (aOR 1.1, 95% CI 1.0 to 1.1; p = 0.02) were independently associated with 30-day mortality. Conclusions: PA infection in ICU is most commonly respiratory and associated with substantial mortality. Existing malignancy, liver disease, and higher APACHE II score were independently associated with mortality.
Historique: L'infection à Pseudomonas aeruginosa (PA) contribue à une mortalité importante en soins intensifs. Dans la présente étude, les chercheurs décrivent l'épidémiologie, les susceptibilités antimicrobiennes et les résultats cliniques des patients atteints d'une infection à Pseudomonas hospitalisés en soins intensifs. Méthodologie: Les chercheurs ont répertorié les patients en soins intensifs atteints d'un PA et les ont classés comme colonisés ou infectés. Ils ont revu les dossiers des patients infectés pour connaître la source de l'infection, les caractéristiques des patients, leurs susceptibilités antimicrobiennes, le bien-fondé d'un traitement antimicrobien empirique et la mortalité au bout de 30 jours. Ils ont déterminé les prédicteurs indépendants de la mortalité au moyen de la régression logistique multivariable. Résultats: Cent quarante patients atteints d'un PA (71 %) étaient infectés. Ils avaient un âge moyen de 55 ans (ÉT 18), et 62 % étaient de sexe masculin. Les hospitalisations étaient d'ordre médical (71 %), chirurgical (20 %) et traumatique-neurologique (9 %). Le score APACHE II (Acute Physiology and Chronic Health Evaluation ou évaluation de la physiologie aiguë et de la santé chronique) s'élevait à 19 (ÉT 10). Cent vingt-six patients (90 %) étaient sous ventilation mécanique, 102 (73 %) dépendaient des vasopresseurs, 27 (19 %) ont reçu une transplantation rénale et 32 (23 %) sont décédés dans les 30 jours. Dans 101 cas (72 %), l'infection était d'origine nosocomiale. L'infection était de source respiratoire (66 %), cutanée-tissus mous (11 %), urinaire (10 %), sanguine (5 %), chirurgicale (5 %), gastro-intestinale (2 %) ou inconnue (1 %). Vingt isolats (14 %) étaient multirésistants et six (4 %), ultrarésistants. Le traitement antimicrobien empirique a été efficace dans 97 cas (69 %). Une maladie hépatique (rapport de cotes corrigé [RCc] 6,2, IC À 95 %, 1,5 à 25,7; p = 0,01), une tumeur maligne (RCc 5,0, IC à 95 %, 1,5 à 17,3; p = 0,01) et un score APACHE II élevé (RCc 1,1, IC à 95 %, 1,0 à 1,1; p = 0,02) étaient liés de façon indépendante à la mortalité au bout de 30 jours. Conclusions: L'infection à PA en soins intensifs est surtout de source respiratoire et associée à une mortalité importante. La préexistence d'une tumeur maligne, d'une maladie hépatique et d'un score APACHE II élevé était liée de façon indépendante à la mortalité.
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We describe the fabrication of metamaterial magnifying hyperlenses with subwavelength wire array structures for operation in the mid-infrared (around 3 µm). The metadevices are composed of approximately 500 tin wires embedded in soda-lime glass, where the metallic wires vary in diameter from 500 nm to 1.2 µm along the tapered structure. The modeling of the hyperlenses indicates that the expected overall losses for the high spatial frequency modes in such metadevices are between 20 dB to 45 dB, depending on the structural parameters selected, being promising candidates for far-field subdiffraction imaging in the mid-infrared. Initial far-field subdiffraction imaging attempts are described, and the problems encountered discussed.
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PURPOSE: A substantial proportion of patients admitted to intensive care units (ICUs) are frail; however, the epidemiology of frailty has not been explored at a population-level. Following implementation of a validated frailty measure into a provincial ICU clinical information system, we describe the population-based prevalence and outcomes of frailty in patients admitted to ICUs. METHODS: Retrospective cohort study of adult admissions to 17 ICUs. Data were captured using eCritical Alberta. A Clinical Frailty Scale (CFS) score assigned at ICU admission was used to define the exposure (CFS score ≥ 5). Primary outcome was hospital mortality. Secondary outcomes were ICU and hospital stay, and receipt of organ support. RESULTS: Fifteen thousand two hundred and thirty-eight patients (81%) were assigned a CFS score at ICU admission. Of these, 28% (95% confidence interval [CI], 27 to 28) were frail. Prevalence of frailty was 9-43% across ICUs. Frail patients were older [mean (standard deviation) 63 (15) vs 56 (17) yr; P < 0.001], more likely to be male (54% vs 46% female; P < 0.001), and had higher APACHE II scores [22 (8) vs 17 (8); P < 0.001] compared with non-frail patients. Frail patients received less mechanical ventilation (62% vs 68%; P < 0.001) and vasoactive therapy (24% vs 57%; P < 0.001), but more non-invasive ventilation (22% vs 9%; P < 0.001). Frail patients had higher hospital mortality (23% vs 9%; adjusted odds ratio, 1.80; 95% CI, 1.64 to 2.05, along with longer ICU stay (median [interquartile range] 4 [2-8] vs 3 [2-6] days; P < 0.001), and longer hospital stay (16 [8-36] vs 10 [5-20] days; P < 0.001) compared with non-frail patients. CONCLUSION: A validated measure of frailty can be implemented at the population level in ICU. Frailty is common in ICU patients and has implications for health service use and clinical outcomes.
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Cuidados Críticos/métodos , Fragilidade/epidemiologia , Unidades de Terapia Intensiva/estatística & dados numéricos , Programas de Rastreamento/métodos , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Alberta , Estudos de Coortes , Feminino , Fragilidade/diagnóstico , Mortalidade Hospitalar , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores SexuaisRESUMO
Hospital capacity strain is ubiquitous, and a significant stressor in critical care. Avoidable days (AD) are frequently used as a metric of capacity. Using a Markov chain model, we studied the relationship between AD and surgical cancellations in a cardiovascular ICU. The model varied the probability of discharging a patient to study this effect over a pool of 108 simulated patients with length of stay data reflecting the actual population. The model behaved as expected with decreasing AD with increasing probability of patient discharge. However, there was no effect on the surgical cancellation rate. We conclude that there is no relationship between AD and critical care capacity as measured by surgical cancellation rate.
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Cuidados Críticos , Cadeias de Markov , Alta do Paciente , Tempo para o Tratamento , Humanos , Unidades de Terapia Intensiva , Tempo de Internação , Procedimentos Cirúrgicos OperatóriosRESUMO
We report the direct femtosecond laser inscription of type-I fiber Bragg gratings (FBGs) into the core of soft-glass ZBLAN fibers. We investigate and compare various fabrication methods such as single pass (line by line), double pass, and stacking (plane by plane) to create the highest reflectivity FBGs (99.98%) for mid-infrared (mid-IR) applications. In addition, we experimentally demonstrate how the parameters that influence the coupling coefficient, i.e., refractive index modulation and overlap factor, can be controlled in these gratings to specifically tailor the FBG properties. The performance of the direct-written type-I gratings after 6 h of annealing is further analyzed, and the reflectivity increases by approximately 10 dB. To the best of our knowledge, this is the first demonstration of temperature-stable mid-IR FBGs with highest coupling coefficient (464 m-1) and lowest loss (<0.5 dB/cm) without the use of an expensive phase mask.
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A review of MRI safety incidents conducted over a 3-year period for a large independent sector diagnostic imaging provider in the UK. The review took a systematic approach using reports logged on an internal incident reporting system that were then categorised and analysed for themes and trends. Notable cases and actions taken are also described from within the period. MRI safety-related events made up 7.5% of the total number of incident reports submitted and 15.5% of all MRI-related reports. The MR safety-related incidence report rate was 0.05% (1 per 1987 patients), which is relatively low considering the number of patients seen in our facilities each day. Internal MRI safety events indicated the main trends to be around referral of contraindicated devices (32% of reports) and failure in the screening process (21.5%-either due to unexpected implants or being unable to confirm safety). To improve practice and work to reduce incidents, advice and instructional materials were developed. The review suggests a potential approach to categorisation of MRI-related safety events which could allow comparisons to be made across organisations, helping to look for trends and guide learning. It also provides insight into the state of MRI safety within the organisation, a rationale for some of the interventions introduced to improve safety, and discussion around common issues arising in MRI safety.
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INTRODUCTION: Physician satisfaction with electronic medical records has often been poor. Usability has frequently been identified as a source for decreased satisfaction. While surveys can identify many issues, and are logistically easier to administer, they may miss issues identified using other methods This study sought to understand the level of physician satisfaction and usability issues associated with a critical care clinical information system (eCritical Alberta) implemented throughout the province of Alberta, Canada. METHOD: All critical care attending physicians using the system were invited to participate in an online survey. Questions included components of the User Acceptance of Information Technology and Usability Questionnaire as well as free text feedback on system components. Physicians were also invited to participate in a think aloud test using simulated scenarios. The transcribed think aloud text and questionnaire were subjected to textual analysis. RESULTS: 82% of all eligible physicians completed the on-line survey (nâ¯=â¯61). Eight physicians were invited and seven completed the think aloud test. Overall satisfaction with the system was moderate. Usability was identified as a significant factor contributing to satisfaction. The major usability factors identified were system response time and layout. The think aloud component identified additional factors beyond those identified in the on-line survey. CONCLUSION: This study found a modestly high level of physician satisfaction with a province-wide clinical critical care information system. Usability continues to be a significant factor in physician satisfaction. Using multiple methods of evaluation can capture the benefits of a large sample size and deeper understanding of the issues.
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Cuidados Críticos , Registros Eletrônicos de Saúde/estatística & dados numéricos , Médicos/psicologia , Padrões de Prática Médica/estatística & dados numéricos , Interface Usuário-Computador , Canadá , Feminino , Humanos , Masculino , Assistência Centrada no Paciente , Satisfação Pessoal , Inquéritos e QuestionáriosRESUMO
We report the development of a widely tunable all-fiber mid-infrared laser system based on a mechanically robust fiber Bragg grating (FBG) which was inscribed through the polymer coating of a Ho3+-Pr3+ co-doped double clad ZBLAN fluoride fiber by focusing femtosecond laser pulses into the core of the fiber without the use of a phase mask. By applying mechanical tension and compression to the FBG while pumping the fiber with an 1150 nm laser diode, a continuous wave (CW) all-fiber laser with a tuning range of 37 nm, centered at 2870 nm, was demonstrated with up to 0.29 W output power. These results pave the way for the realization of compact and robust mid-infrared fiber laser systems for real-world applications in spectroscopy and medicine.
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The major task of physicians is decision making. This is often done in time pressured situations. The traditional theory of decision making does not reflect this reality and naturalistic decision making is a more appropriate model. The first step is to make sense of the patient or the problem and the Data-Frame Theory of Klein seems to be the best model. This model has significant implications in the way we view clinical information systems, communication and medical education.