92 research outputs found

    Broadband Tuning (170nm) of InGaAs Quantum Well Lasers

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    The wavelength tuning properties of strained InGaAs quantum well lasers using an external grating for feedback is reported. Tunable laser oscillation has been observed over a range of 170 nm, between 840 and 1010 nm, under pulsed current excitation. The optimal conditions for broadband tunability for the InGaAs lasers are different from GaAs lasers, which is attributed to a difference in spectral gain curves. Together with an optimised GaAs quantum well laser the entire region between 740 and 1010 nm is spanned

    Broadband tunability of gain-flattened quantum well semiconductor lasers with an external grating

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    Quantum well lasers are shown to exhibit flattened broadband gain spectra at a particular pumping condition. The gain requirement for a grating-tuned external cavity configuration is examined and applied to a semiconductor quantum well laser with an optimized length of gain region. The predicted very broadband tunability of quantum well lasers is confirmed experimentally by grating-tuning of uncoated lasers over 85 nm, with single longitudinal mode output power exceeding 200 mW

    Optimised Fabry-Perot (AlGa)As quantum well lasers tunable over 105 nm

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    Uncoated, Fabry-Perot (AlGa)As semiconductor lasers are tuned over 105nm in a grating-coupled external cavity. Broadband tunability is achieved by optimising the resonator loss so as to invoke lasing from both the first and second quantised states of the single quantum well active region

    PHS63 Cost-Effectiveness Analysis Of A Pharmacist-Led Intervention On Improving Inhaler Adherence In Patients With Chronic Obstructive Pulmonary Disease

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    Objectives: The Belgian community pharmacist-led PHARMACOP intervention provided educational inhalation training sessions and motivational interviewing regarding medication use in patients with Chronic Obstructive Pulmonary Disease (COPD). The program significantly improved medication adherence and inhalation techniques compared with usual care. This study aimed to evaluate its costeffectiveness. Methods: An economic analysis was performed from the Belgian health care payer's perspective. A Markov model was constructed in which a cohort of 1,000 patients with COPD receiving the 3-month PHARMACOP-intervention or usual care, was followed. This cohort had a mean age of 70 years, 66% were male, 43% current smokers and patients had a mean Forced Expiratory Volume in 1 second of % predicted of 50. Three types of costs were calculated: intervention costs, medication costs and exacerbation costs. Outcome measures included the number of hospital-treated exacerbations, cost per prevented hospital-treated exacerbation and cost per Quality Adjusted Life-Year (QALY) gained. Follow-up was 1 year in the basecase analysis. Univariate-, probabilistic sensitivity- and scenario analyses (including long-term follow-up) were performed to assess uncertainty. Results: In the basecase analysis, the average overall costs per patient for the PHARMACOPintervention and usual care were € 2,221 and € 2,448, respectively within the 1-year time horizon. This reflects cost savings of € 227 for the PHARMACOP-intervention. The PHARMACOP-intervention resulted in the prevention of 71 hospital-treated exacerbations (167 for PHARMACOP versus 238 for usual care), i.e. 0.07 (95%CI: 0.04-0.10) incremental hospital-treated exacerbations per patient. In addition, a small (<0.001 QALYs) increase in QALYs was observed. Results showed robust costsavings in various sensitivity analyses. Conclusions: Optimization of current pharmacotherapy (e.g. close monitoring of inhalation technique and medication adherence) has been shown to be cost-saving and should be considered before adding new therapies

    Guiding neutral atoms around curves with lithographically patterned current-carrying wires

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    Laser-cooled neutral atoms from a low-velocity atomic source are guided via a magnetic field generated between two parallel wires on a glass substrate. The atoms bend around three curves, each with a 15-cm radius of curvature, while traveling along a 10-cm-long track. A maximum flux of 2*10^6 atoms/sec is achieved with a current density of 3*10^4 A/cm^2 in the 100x100-micrometer-cross-section wires. The kinetic energy of the guided atoms in one transverse dimension is measured to be 42 microKelvin.Comment: 9 page

    Knowledge of actions of inhaled corticosteroids in patients who did not persist drug treatment early

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    Objective To evaluate, among new users of inhaled corticosteroids that did not persist treatment, knowledge of inhaled corticosteroids' actions and whether they were instructed on the use of their inhaler. Setting Fifteen community pharmacies in The Netherlands. Methods Patients were interviewed by telephone. Their general practitioners provided diagnostic information and automated dispensing records were retrieved. Main outcome measures Knowledge of patients about the actions of inhaled corticosteroids. Results 230 (80.1%) of 287 patients were willing to participate. The majority (79.1%) of 230 patients was not aware of the anti-inflammatory actions of inhaled corticosteroids. Most patients were instructed on the use of their inhaler, predominantly by their physician (53%) or pharmacy (35.2%). Conclusions Although most patients reported inhaler instruction by at least one health care provider, the majority was unaware of inhaled corticosteroids' actions. Physicians and pharmacists should reconsider the instructions they provide especially to patients who should continuously use inhaled corticosteroids

    Comparison of serious inhaler technique errors made by device-naĂŻve patients using three different dry powder inhalers: a randomised, crossover, open-label study

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    Background: Serious inhaler technique errors can impair drug delivery to the lungs. This randomised, crossover, open-label study evaluated the proportion of patients making predefined serious errors with Pulmojet compared with Diskus and Turbohaler dry powder inhalers. Methods: Patients ≄18 years old with asthma and/or COPD who were current users of an inhaler but naĂŻve to the study devices were assigned to inhaler technique assessment on Pulmojet and either Diskus or Turbohaler in a randomised order. Patients inhaled through empty devices after reading the patient information leaflet. If serious errors potentially affecting dose delivery were recorded, they repeated the inhalations after watching a training video. Inhaler technique was assessed by a trained nurse observer and an electronic inhalation profile recorder. Results: Baseline patient characteristics were similar between randomisation arms for the Pulmojet-Diskus (n = 277) and Pulmojet-Turbohaler (n = 144) comparisons. Non-inferiority in the proportions of patients recording no nurse-observed serious errors was demonstrated for both Pulmojet versus Diskus, and Pulmojet versus Turbohaler; therefore, superiority was tested. Patients were significantly less likely to make ≄1 nurse-observed serious errors using Pulmojet compared with Diskus (odds ratio, 0.31; 95 % CI, 0.19–0.51) or Pulmojet compared with Turbohaler (0.23; 0.12–0.44) after reading the patient information leaflet with additional video instruction, if required. Conclusions These results suggest Pulmojet is easier to learn to use correctly than the Turbohaler or Diskus for current inhaler users switching to a new dry powder inhaler
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