58 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

    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

    Ultrabroadband tunable external-cavity quantum well lasers

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    The spectral tunability of properly designed quantum well lasers is demonstrated to equal the range of dye lasers. Theoretical and measured gain spectra are presented to support this statement, and stepwise wavelength tuning over a 125 nm span in GaAs/AlGaAs lasers and 175 nm in InGaAs/AlGaAs lasers are shown

    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

    Self-stabilized nonlinear lateral modes of broad area lasers

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    Comparison of serious inhaler technique errors made by device-naïve 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 naïve 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

    A drop-in clinic for patients with poorly-controlled diabetes: a community pharmacy feasibility study

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    Background Preparatory work suggests that there may be a role for the pharmacist in managing sub-optimal medication adherence and dose titration of prescribed medicines in patients with type 2 diabetes. Patients have reported that they are receptive towards pharmacists becoming involved in their care providing that this is integrated into the care received from their medical practice. Objective To determine whether a community pharmacy diabetes drop-in clinic is feasible and acceptable to patients with poorly controlled type 2 diabetes. Setting Five community pharmacies in Norfolk, UK. Method Poorly controlled patients, as defined by a national General Practitioner incentive scheme, were invited to participate in the study by a letter posted by their medical practice. One four-hour, pharmacist clinic, where participants were able to "drop-in", was conducted in five pharmacies every week for four to six weeks. Questionnaires before and after the consultation were used to determine the clinic's effect on satisfaction with, and beliefs about, medicines and adherence along with participant satisfaction. Pharmacists had the opportunity to provide feedback via "debrief" interviews. Main outcome measure As a feasibility study, a combination of outcomes were explored including informationsatisfaction and adherence. Results Thirty-three (9.6%) of the 342 patients with type 2 diabetes posted letters were recruited from four pharmacies. Follow-up questionnaire completion rate was 88%. The clinic demonstrated little change in the parameters measured over three months. All of the participants rated their general impression of the service as good or very good and all would be happy to recommend the service to others with diabetes. Sixteen participants (59%) stated that it would make them more likely to consult their pharmacist in the future. Pharmacists enjoyed providing the service as it allowed them to interact more formally, and for longer, with patients. Conclusion This research has demonstrated that a community pharmacy drop-in clinic is feasible and likely to be acceptable to both patients and pharmacists; however, cost effectiveness of such a service should be explored in future studies. Further thought should also be given to how this service can complement that provided by a nurse in the medical practice and how the pharmacist can provide additional benefit to the NHS

    A cluster randomised control trial to evaluate the effectiveness and cost-effectiveness of the Italian medicines use review (I-MUR) for asthma patients

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    Background The economic burden of asthma, which relates to the degree of control, is €5 billion annually in Italy. Pharmacists could help improve asthma control, reducing this burden. This study aimed to evaluate the effectiveness and cost-effectiveness of Medicines Use Reviews provided by community pharmacists in asthma. Methods This cluster randomised, multi-centre, controlled trial in adult patients with asthma was conducted in 15 of the 20 regions of Italy between September 2014 and July 2015. After stratification by region, community pharmacists were randomly allocated to group A (trained in and delivered the intervention at baseline) or B (training and delivery 3 months later), using computerised random number generation in blocks of 10. Each recruited up to five patients, with both groups followed for 9 months. The intervention consisted of a systematic, structured face-to-face consultation with a pharmacist, covering asthma symptoms, medicines used, attitude towards medicines and adherence, recording pharmacist-identified pharmaceutical care issues (PCIs). The primary outcome was asthma control, assessed using the Asthma-Control-Test (ACT) score (ACT ≥ 20 represents good control). Secondary outcomes were: number of active ingredients, adherence, cost-effectiveness compared with usual care. Although blinding was not possible for either pharmacists or patients, assessment of outcomes was conducted by researchers blind to group allocation. Results Numbers of pharmacists and patients enrolled were 283 (A = 136; B = 147) and 1263 (A = 600; B = 663), numbers completing were 201 (A = 97; B = 104) and 816 (A = 400; B = 416), respectively. Patients were similar in age and gender and 56.13% (458/816) had poor/partial asthma control. Pharmacists identified 1256 PCIs (mean 1.54/patient), mostly need for education, monitoring and potentially ineffective therapy. Median ACT score at baseline differed between groups (A = 19, B = 18; p < 0.01). Odds ratio for improved asthma control was 1.76 (95% CI 1.33–2.33) and number needed to treat 10 (95% CI 6–28). Number of active ingredients reduced by 7.9% post-intervention (p < 0.01). Adherence improved by 35.4% 3 months post-intervention and 40.0% at 6 months (p < 0.01). The probability of the intervention being more cost-effective than usual care was 100% at 9 months. Conclusions This community pharmacist-based intervention demonstrated both effectiveness and cost-effectiveness. It has since been implemented as the first community pharmacy cognitive service in Italy
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