| 1. |
- Hashemi, Seyed Ehsan, 1986, et al.
(författare)
-
Triggering of guiding and antiguiding effects in GaN-based VCSELs
- 2014
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 9001
-
Konferensbidrag (refereegranskat)abstract
- We show numerically that many recently proposed GaN-based VCSEL cavities, with DBR mirrors deposited onto the current aperture, balance dangerously close to the border between the guided and antiguided regime. A guided cavity is often preferred because of its lower optical loss, but a strongly antiguided cavity offers built-in modal discrimination favoring single fundamental mode operation. We show that very small changes in the VCSEL structure are sufficient to strongly change the guiding character of the VCSEL cavity, and that thermal lensing caused by device self-heating under operation can dramatically reduce the optical loss but not the modal discrimination in the antiguided cavities.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Gierl, Christian, et al.
(författare)
-
Tuneable VCSEL aiming for the application in interconnects and short haul systems
- 2011
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819484963 ; 7959
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Widely tunable vertical cavity surface emitting lasers (VCSEL) are of high interest for optical communications, gas spectroscopy and fiber-Bragg-grating measurements. In this paper we present tunable VCSEL operating at wavelength around 850 nm and 1550 nm with tuning ranges up to 20 nm and 76 nm respectively. The first versions of VCSEL operating at 1550 nm with 76 nm tuning range and an output power of 1.3mW were not designed for high speed modulation, but for applications where only stable continious tuning is essential (e.g. gas sensing). The next step was the design of non tunable VCSEL showing high speed modulation frequencies of 10 GHz with side mode supression ratios beyond 50 dB. The latest version of these devices show record output powers of 6.7mW at 20 °C and 3mW at 80 °C. The emphasis of our present and future work lies on the combination of both technologies. The tunable VCSEL operating in the 850 nm-region reaches a modulation bandwidth of 5.5GHz with an output power of 0.8mW.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Bowers, L., et al.
(författare)
-
Locked doors : a survey of patients, staff and visitors
- 2010
-
Ingår i: Journal of Psychiatric and Mental Health Nursing. - : Wiley. - 1351-0126 .- 1365-2850. ; 17:10, s. 873-880
-
Tidskriftsartikel (refereegranskat)abstract
- Locking the door of adult acute psychiatric wards has become increasingly common in the UK. There has been little investigation of its efficacy or acceptability in comparison to other containment methods. We surveyed the beliefs and attitudes of patients, staff and visitors to the practice of door locking in acute psychiatry. Wards that previously participated in a previous study were contacted and sent a questionnaire. A total of 1227 responses were obtained, with the highest number coming from staff, and the smallest from visitors. Analysis identified five factors (adverse effects, staff benefits, patient safety benefits, patient comforts and cold milieu). Patients were more negative about door locking than the staff, and more likely to express such negative judgments if they were residing in a locked ward. For staff, being on a locked ward was associated with more positive judgments about the practice. There were significant age, gender and ethnicity effects for staff only. Each group saw the issue of locked doors from their own perspective. Patients registered more anger, irritation and depression as a consequence of locked doors than staff or visitors thought they experienced. These differences were accentuated by the actual experience of the ward being locked.
|
|
| 11. |
- Davani, Hooman A., et al.
(författare)
-
Polarization investigation of a tunable high-speed short-wavelength bulk-micromachined MEMS-VCSEL
- 2012
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819489197 ; 8276, s. Art. no. 82760T-
-
Konferensbidrag (refereegranskat)abstract
- We report the investigation of the state of polarization (SOP) of a tunable vertical-cavity surface-emitting laser (VCSEL) operating near 850 nm with a mode-hop free single-mode tuning range of about 12 nm and an amplitude modulation bandwidth of about 5 GHz. In addition, the effect of a sub-wavelength grating on the device and its influence on the polarization stability and polarization switching has been investigated. The VCSEL with an integrated sub-wavelength grating shows a stable SOP with a polarization mode suppression ratio (PMSR) more than 35 dB during the tuning.
|
|
| 12. |
|
|
| 13. |
- Feng, L, et al.
(författare)
-
Technique for strand-specific gene-expression analysis and monitoring of primer-independent cDNA synthesis in reverse transcription
- 2012
-
Ingår i: BioTechniques. - : Future Science Ltd. - 1940-9818 .- 0736-6205. ; 52:4, s. 263-
-
Tidskriftsartikel (refereegranskat)abstract
- Primer-independent cDNA synthesis during reverse transcription hinders quantitative analysis of bidirectional mRNA synthesis in eukaryotes as well as in cells infected with RNA viruses. We report a simple RT-PCR-based assay for strand-specific gene-expression analysis. By modifying the cDNA sequence during reverse transcription, the opposite strands of target sequences can be simultaneously detected by postamplification melting curve analysis and primer-initiated transcripts are readily distinguished from nonspecifically primed cDNA. We have utilized this technique to optimize the specificity of reverse transcription on a panel of 15 target genes. Primer-independent reverse transcription occurred for all target sequences when reverse transcription was performed at 42°C and accounted for 11%–57% of the final PCR amplification products. By raising the reaction temperature to 55°C, the specificity of reverse transcription could be increased without significant loss of sensitivity. We have also demonstrated the utility of this technique for analysis of (+) and (-) RNA synthesis of influenza A virus in infected cells. Thus, this technique represents a powerful tool for analysis of bidirectional RNA synthesis.
|
|
| 14. |
|
|
| 15. |
- Haglund, Lotta, et al.
(författare)
-
International trends in health science librarianship : part 3--the Nordic countries.
- 2012
-
Ingår i: Health Information and Libraries Journal. - : Wiley. - 1471-1834 .- 1471-1842. ; 29:3, s. 247-51
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This is the third in a series of articles exploring international trends in health science librarianship in the first decade of the 21st century. The invited authors carried out a survey of librarians in Sweden, Denmark, Norway and Finland to identify common developments in their countries. A focus on pedagogy was seen as the most important trend. Future issues will track trends in Southern Europe and Latin America. JM.
|
|
| 16. |
- Loos, Robert, et al.
(författare)
-
EU-wide monitoring survey on emerging polar organic contaminants in wastewater treatment plant effluents
- 2013
-
Ingår i: Water Research. - : Elsevier. - 0043-1354 .- 1879-2448. ; 47:17, s. 6475-6487
-
Tidskriftsartikel (refereegranskat)abstract
- In the year 2010, effluents from 90 European wastewater treatment plants (WWTPs) were analyzed for 156 polar organic chemical contaminants. The analyses were complemented by effect-based monitoring approaches aiming at estrogenicity and dioxin-like toxicity analyzed by in vitro reporter gene bioassays, and yeast and diatom culture acute toxicity optical bioassays. Analyses of organic substances were performed by solid-phase extraction (SPE) or liquid-liquid extraction (LLE) followed by liquid chromatography tandem mass spectrometry (LC-MS-MS) or gas chromatography high-resolution mass spectrometry (GC-HRMS). Target microcontaminants were pharmaceuticals and personal care products (PPCPs), veterinary (antibiotic) drugs, perfluoroalkyl substances (PFASs), organophosphate ester flame retardants, pesticides (and some metabolites), industrial chemicals such as benzotriazoles (corrosion inhibitors), iodinated x-ray contrast agents, and gadolinium magnetic resonance imaging agents; in addition biological endpoints were measured. The obtained results show the presence of 125 substances (80% of the target compounds) in European wastewater effluents, in concentrations ranging from low nanograms to milligrams per liter. These results allow for an estimation to be made of a European median level for the chemicals investigated in WWTP effluents. The most relevant compounds in the effluent waters with the highest median concentration levels were the artificial sweeteners acesulfame and sucralose, benzotriazoles (corrosion inhibitors), several organophosphate ester flame retardants and plasticizers (e.g. tris(2-chloroisopropyl)phosphate; TCPP), pharmaceutical compounds such as carbamazepine, tramadol, telmisartan, venlafaxine, irbesartan, fluconazole, oxazepam, fexofenadine, diclofenac, citalopram, codeine, bisoprolol, eprosartan, the antibiotics trimethoprim, ciprofloxacine, sulfamethoxazole, and clindamycine, the insect repellent N,N'-diethyltoluamide (DEET), the pesticides MCPA and mecoprop, perfluoroalkyl substances (such as PFOS and PFOA), caffeine, and gadolinium.
|
|
| 17. |
|
|
| 18. |
- Nijman, H., et al.
(författare)
-
Door locking and exit security measures on acute psychiatric admission wards
- 2011
-
Ingår i: Journal of Psychiatric and Mental Health Nursing. - : Wiley. - 1351-0126 .- 1365-2850. ; 18:7, s. 614-621
-
Tidskriftsartikel (refereegranskat)abstract
- Locking the exit doors of psychiatric wards is believed to reduce the risk of patients absconding. The aims of the study were to investigate both the prevalence of door locking and other exit security measures on UK admission wards, as well as whether door locking appears to be effective in keeping inpatients in. A cross-sectional survey on 136 acute psychiatric wards in the UK was conducted, in which a range of data on patients, staff, and conflict and containment events, including door locking and absconding, were collected from shift to shift during a period of 6 months. About one-third of the participating wards (30%) operated with their ward exit door permanently locked, whereas another third (34%) never locked the ward door. Univariate analyses suggested little association between exit security measures and absconding. A more robust multilevel statistical analysis, however, did indicate a reduction of about 30% of absconding rates when the ward door was locked the entire shift. Although locking the ward door does seem to reduce absconding to a certain extent, it far from completely prevents it. As it may be unrealistic to strive for a 100% absconding-proof ward, alternative measures for door locking to prevent absconding are discussed.
|
|
| 19. |
- Rostkowski, P., et al.
(författare)
-
Non-target screening of environmental samples by low and high resolution time of flight mass spectrometry (TOF-MS)
- 2013
-
Ingår i: Proceedings of the 13th International Conference on Environmental Science and Technology. - : Global Nest, Secretariat. - 9789607475510
-
Konferensbidrag (refereegranskat)abstract
- The already substantial number of different organic chemical substances emitted to, and circulating in the environment is increasing. Due both to this growing number of chemicals, and the accumulating knowledge of their potential negative environmental and health effects, the number of emerging contaminants in Europe and elsewhere is also increasing. In regular environmental analysis, a targeted approach is generally used, i.e. the analytes of interest are selected before making measurements. However, the problem with targeted methods is that chemicals, which are not initially anticipated, are not detected regardless of how high their concentration might be. Thus the non-target approaches are needed to identify the unknowns and to reveal a more complete profile of contaminants. In this study we utilized modern techniques, such as high and low resolution time of flight mass spectrometry (TOF-MS) combined with either ultra-high-performance liquid chromatography (UPLC), gas chromatography (GC) or multidimensional gas chromatography (GCxGC) to analyze wastewater, sludge, sediment and biota samples. This approach proved to be useful, a number of anthropogenic compounds have been tentatively identified and included: pharmaceuticals and personal care products, plasticizers and flame retardants, polymer additives, and other well-known persistent organic pollutants. Additionally, full-scan acquisition allows retrospective analysis for emerging contaminants years after the data has been acquired.
|
|
| 20. |
- Shimokawa, Noriaki, et al.
(författare)
-
CIN85 regulates dopamine receptor endocytosis and governs behaviour in mice
- 2010
-
Ingår i: EMBO Journal. - : European Molecular Biology Organization. - 0261-4189 .- 1460-2075. ; 29:14, s. 2421-2432
-
Tidskriftsartikel (refereegranskat)abstract
- Despite extensive investigations of Cbl-interacting protein of 85 kDa (CIN85) in receptor trafficking and cytoskeletal dynamics, little is known about its functions in vivo. Here, we report the study of a mouse deficient of the two CIN85 isoforms expressed in the central nervous system, exposing a function of CIN85 in dopamine receptor endocytosis. Mice lacking CIN85 exon 2 (CIN85(Deltaex2)) show hyperactivity phenotypes, characterized by increased physical activity and exploratory behaviour. Interestingly, CIN85(Deltaex2) animals display abnormally high levels of dopamine and D2 dopamine receptors (D2DRs) in the striatum, an important centre for the coordination of animal behaviour. Importantly, CIN85 localizes to the post-synaptic compartment of striatal neurons in which it co-clusters with D2DRs. Moreover, it interacts with endocytic regulators such as dynamin and endophilins in the striatum. Absence of striatal CIN85 causes insufficient complex formation of endophilins with D2DRs in the striatum and ultimately decreased D2DR endocytosis in striatal neurons in response to dopamine stimulation. These findings indicate an important function of CIN85 in the regulation of dopamine receptor functions and provide a molecular explanation for the hyperactive behaviour of CIN85(Deltaex2) mice.
|
|
| 21. |
- Sun, Jie, 1977, et al.
(författare)
-
Direct Chemical Vapor Deposition of Large-Area Carbon Thin Films on Gallium Nitride for Transparent Electrodes: A First Attempt
- 2012
-
Ingår i: IEEE Transactions on Semiconductor Manufacturing. - : Institute of Electrical and Electronics Engineers (IEEE). - 0894-6507 .- 1558-2345. ; 25:3, s. 494-501
-
Tidskriftsartikel (refereegranskat)abstract
- Direct formation of large-area carbon thin films on gallium nitride by chemical vapor deposition without metallic catalysts is demonstrated. A high flow of ammonia is used to stabilize the surface of the GaN (0001)/sapphire substrate during the deposition at 950 degrees C. Various characterization methods verify that the synthesized thin films are largely sp(2) bonded, macroscopically uniform, and electrically conducting. The carbon thin films possess optical transparencies comparable to that of exfoliated graphene. This paper offers a viable route toward the use of carbon-based materials for future transparent electrodes in III-nitride optoelectronics, such as GaN-based light emitting diodes and laser diodes.
|
|
| 22. |
|
|
| 23. |
- Westbergh, Petter, 1981, et al.
(författare)
-
High-speed 850 nm VCSELs with 28 GHz modulation bandwidth operating error-free up to 44 Gbit/s
- 2012
-
Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 48:18, s. 1145-U178
-
Tidskriftsartikel (refereegranskat)abstract
- A new generation of high-speed oxide confined 850 nm vertical cavity surface-emitting lasers is presented. A record high modulation bandwidth of 28 GHz is achieved and error-free data transmission at bit-rates up to 44 Gbit/s is demonstrated.
|
|
| 24. |
- Westbergh, Petter, 1981, et al.
(författare)
-
High-Speed Oxide Confined 850-nm VCSELs Operating Error-Free at 40 Gb/s up to 85 degrees C
- 2013
-
Ingår i: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 25:8, s. 768-771
-
Tidskriftsartikel (refereegranskat)abstract
- We present the temperature dependence of the performance characteristics of our latest generation high-speed oxide confined 850-nm vertical cavity surface-emitting lasers (VCSELs). Using a 7-mu m oxide aperture diameter VCSEL, we demonstrate a maximum modulation bandwidth of similar to 27 GHz at room temperature and similar to 21 GHz at 85 degrees C. With a new highspeed optical receiver, these bandwidths enable error-free data transmission ( defined as a bit-error-rate
|
|
| 25. |
- Zavareh, DK, et al.
(författare)
-
ROAD SAFETY
- 2010
-
Ingår i: INJURY PREVENTION. - 1353-8047. ; 16, s. A53-A53
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
|
| 26. |
|
|
