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- Carlsson, C., et al.
(författare)
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Performance characteristics of buried heterostructure VCSELs using semi-insulating GaInP : Fe regrowth
- 2001
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Ingår i: IEEE Journal of Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9197 .- 1558-1713. ; 37:7, s. 945-950
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Tidskriftsartikel (refereegranskat)abstract
- We have fabricated GaAs-AlGaAs buried heterostructure vertical cavity surface emitting lasers, emitting at 850 nm, using semi-insulating GaInP:Fe regrowth and investigated their static properties. Lasers of different size (10-21 mum) have threshold currents in the range 2.8-7.0 mA, and produce a maximum output power of 1.7-6.0 mW at room temperature. The variation of threshold current with device size shows that the leakage current at the regrowth interface accounts for a significant part of the injection current. In spite of this, a differential quantum efficiency in the range 20%-30% is obtained which indicates that the regrowth interface is smooth and does not introduce any significant scattering loss. Studies of the transverse mode properties suggest that the GaInP provides weak guiding, resulting in single mode operation up to an output power of 0.7 mW and a beam divergence of only 6 degrees for lasers as large as 10 mum.
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| 4. |
- Angulo Barrios, C., et al.
(författare)
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GaAs/AlGaAs buried-heterostructure laser diodes with semi-insulating GaInP:Fe regrowth
- 2001
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Ingår i: Lasers and Electro-Optics, 2001. CLEO/Pacific Rim 2001. The 4th Pacific Rim Conference on.
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Konferensbidrag (refereegranskat)abstract
- GaAs/AlGaAs buried-heterostructure in-plane lasers and vertical-cavity surface-emitting lasers using GaInP:Fe as the burying layer have been fabricated and investigated. Regrowth of GaInP:Fe around etched laser mesas was achieved by hydride vapor phase epitaxy. The lasers exhibit good performance under CW operation and show promising high-speed characteristics.
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| 8. |
- Wattwil, Magnus, et al.
(författare)
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Dexamethasone is as effective as ondansetron for the prevention of postoperative nausea and vomiting following breast surgery
- 2003
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172 .- 1399-6576. ; 47:7, s. 823-827
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Postoperative nausea and vomiting remain a common problem following breast surgery. This study assesses whether dexamethasone is as effective as ondansetron in the control of postoperative nausea and vomiting (PONV). Methods: Eighty ASA I-III patients undergoing breast surgery for carcinoma of the breast were included in the study. Following premedication with diazepam 5-10 mg, patients were induced with fentanyl 50 µg and propofol 2-2.5 mg kg-1. A larynx mask was inserted and anesthesia maintained with sevoflurane in oxygen and nitrous oxide. Patients were then randomly divided into two groups: Group D (dexamethasone) was given 4 mg dexamethasone i.v. after induction and Group O (ondansetron) was given 4 mg ondansetron at the same time point. Postoperatively, nausea, vomiting and pain were recorded at 1-h intervals during 4 h, and thereafter every 4h during 24 h. Results: The incidence of PONV during 24h was 37% and 33% in Group D and Group O, respectively (NS). No differences were found between the groups in the incidence of post-operative nausea, vomiting or pain at the different time intervals. No differences were found in the incidence of PONV in smokers vs. non-smokers. No side-effects of these drugs were observed. Conclusions: Ondansetron 4 mg or dexamethasone 4 mg are equally effective in the prevention of postoperative nausea and vomiting following breast surgery. Other factors being similar, the difference in cost between these drugs would favor the use of dexamethasone instead of ondansetron when monotherapy against PONV is used. © Acta Anaesthesiologica Scandinavica.
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| 9. |
- Tolmachev, V, et al.
(författare)
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Production of Br-76 by a low-energy cyclotron
- 1998
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Ingår i: APPLIED RADIATION AND ISOTOPES. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0969-8043. ; 49:12, s. 1537-1540
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We present a production method of a positron-emitting bromine isotope Br-76 (T-1/2 = 16.2 h) using a low-energy proton reaction Se-76(p, n)Br-76. A pressed copper (I) selenide pellet containing enriched Se-76 is used as a target. Irradiation of a 180 mg/c
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| 10. |
- Wattwil, Magnus, et al.
(författare)
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Perioperative gastric emptying is not a predictor of early postoperative nausea and vomiting in patients undergoing laparoscopic cholecystectomy
- 2002
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Ingår i: Anesthesia and Analgesia. - : Ovid Technologies (Wolters Kluwer Health). - 0003-2999 .- 1526-7598. ; 95:2, s. 476-479
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Tidskriftsartikel (refereegranskat)abstract
- It is not known whether patients with postoperative nausea and vomiting (PONV) have delayed gastric emptying compared with patients without PONV. We compared the perioperative rate of gastric emptying in patients experiencing PONV with the rate in those without PONV immediately after laparoscopic cholecystectomy. Gastric emptying was studied by the acetaminophen method. Acetaminophen is not absorbed from the stomach but is rapidly absorbed from the small intestine, and the rate of gastric emptying therefore determines the rate of absorption of acetaminophen administered into the stomach. Forty patients (ASA physical status I and II) were included in the study. After the induction of anesthesia, a gastric tube was positioned in the stomach and 1.5 g of acetaminophen dissolved in 200 mL of water was administered. Venous blood samples for the determination of serum acetaminophen concentrations were taken before and at 15-min intervals during a period of 180 min after the administration of acetaminophen. Twenty-six patients experienced nausea during the first 4 h postoperatively. The other 14 patients had no nausea. There were no statistically significant differences in the maximal acetaminophen concentration, the time taken to reach the maximal concentration, or the area under the serum acetaminophen concentration time curves from 0 to 60, 0-120, and 0-180 min between the groups of patients with or without PONV. We did not find any relationship between postoperative gastric emptying and PONV, and therefore gastric emptying is not a predictor of PONV.
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