| 1. |
- Lloyd-Spets, Anita, et al.
(författare)
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MISiCFET chemical gas sensors for high temperature and corrosive environment applications
- 2002
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Ingår i: Materials Science Forum. - 0255-5476 .- 1662-9752. ; 389-3, s. 1415-1418
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Tidskriftsartikel (refereegranskat)abstract
- A chemical gas sensor based on a silicon carbide field effect transistor with a catalytic gate metal has been under development for a number of years. The buried gate design allows the sensor to operate at high temperatures, routinely up to 600degreesC and for at least three days at 700degreesC. The chemical inertness of silicon carbide makes it a suitable sensor technology for applications in corrosive environments such as exhaust gases and flue gases from boilers. The selectivity of the sensor devices is established through the choice of type and structure of the gate metal as well as the operation temperature. In this way NH3 sensors with low cross sensitivity to NOx have been demonstrated as potential sensors for control of selective catalytic reduction (SCR) of NOx by urea injection into diesel exhausts. The hardness of the silicon carbide makes it for example more resistant to water splash at cold start of a petrol engine than existing technologies, and a sensor which can control the air to fuel ratio, before the exhaust gases are heated, has been demonstrated. Silicon carbide sensors are also tested in flue gases from boilers. Efficient regulation of the combustion in a boiler will decrease fuel consumption and reduce emissions.
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| 2. |
- Lloyd-Spets, Anita, et al.
(författare)
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SiC based field effect gas sensors for industrial applications
- 2001
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Ingår i: Physica status solidi. A, Applied research. - 0031-8965 .- 1521-396X. ; 185:1, s. 15-25
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Tidskriftsartikel (refereegranskat)abstract
- The development and field-testing of high-temperature sensors based on silicon carbide devices have shown promising results in several application areas. Silicon carbide based field-effect sensors can be operated over a large temperature range, 100-600 degreesC, and since silicon carbide is a chemically very inert material these sensors can be used in environments like exhaust gases and flue gases from boilers. The sensors respond to reducing gases like hydrogen, hydrocarbons and carbon monoxide. The use of different temperatures, different catalytic metals and different structures of the gate metal gives selectivity to different gases and arrays of sensors can be used to identify and monitor several components in gas mixtures. MOSFET sensors based on SIC combine the advantage of simple circuitry with a thicker insulator, which increases the long term stability of the devices. In this paper we describe silicon carbide MOSFET sensors and their performance and give: examples of industrial applications such as monitoring of car exhausts and flue gases. Chemometric methods have been used for the evaluation of the data.
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| 3. |
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| 4. |
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| 5. |
- Baranzahi, Amir, et al.
(författare)
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Response of metal-oxide-silicon carbide sensors to simulated and real exhaust gases
- 1997
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 43:1-3, s. 52-59
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Tidskriftsartikel (refereegranskat)abstract
- Field effect devices based on catalytic metal-oxide-silicon carbide (MOSiC) structures can be used as high temperature gas sensors. The devices are sensitive to hydrocarbons and hydrogen and can be operated up to at least 900 degrees C, which make them suitable for several combustion applications, Simulated and real exhaust gases from a car engine have been studied at sensor temperatures from 200 to 650 degrees C, and it was round that the sensor signal is high for excess hydrocarbon and low for excess oxygen. The response time is less than 100 ms and only a small degradation of the devices was observed after several days of operation. The devices also react to changes of the gas composition In the fuel-rich and fuel-lean region. The devices show an interesting temperature dependence in the fuel rich region.
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| 6. |
- Kaiser, M., et al.
(författare)
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VEDLIoT: Very Efficient Deep Learning in IoT
- 2022
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Ingår i: Proceedings of the 2022 Design, Automation and Test in Europe Conference and Exhibition, DATE 2022. - : IEEE. - 9783981926361
-
Konferensbidrag (refereegranskat)abstract
- The VEDLIoT project targets the development of energy-efficient Deep Learning for distributed AIoT applications. A holistic approach is used to optimize algorithms while also dealing with safety and security challenges. The approach is based on a modular and scalable cognitive IoT hardware platform. Using modular microserver technology enables the user to configure the hardware to satisfy a wide range of applications. VEDLIoT offers a complete design flow for Next-Generation IoT devices required for collaboratively solving complex Deep Learning applications across distributed systems. The methods are tested on various use-cases ranging from Smart Home to Automotive and Industrial IoT appliances. VEDLIoT is an H2020 EU project which started in November 2020. It is currently in an intermediate stage with the first results available.
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| 7. |
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| 8. |
- Sagalowicz, Laurent, et al.
(författare)
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Structure of the wafer fused InP (001)-GaAs (001) interface
- 1997
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Ingår i: Philosophical Magazine Letters. - : Informa UK Limited. - 0950-0839 .- 1362-3036. ; 76:6, s. 445-452
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Tidskriftsartikel (refereegranskat)abstract
- A structural study of wafer fused InP-GaAs interfaces has been carried out. The geometry of the dislocation network which accommodates the twist and the lattice mismatch is first given using a geometrical approach. Cross-sectional transmission electron microscopy and plan view observations are presented. Two different misfit cases are observed. (1) When no twist is present, the 3.7% lattice mismatch is relaxed by a regular square network of dislocations with pure edge character. (2) When an additional twist is present, a square network of dislocations results as well but here the dislocations have a mixed character; 60° dislocations are also observed, some form closed defect circuits and others very likely accommodate a small tilt. The interaction between the 60° dislocations and the edge dislocations is explained in detail. Voids or inclusions are also observed as well as additional dislocations which may accommodate part of the thermal mismatch. © 1997 Taylor & Francis Ltd.
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| 9. |
- Salami, B., et al.
(författare)
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LEGaTO: Low-Energy, Secure, and Resilient Toolset for Heterogeneous Computing
- 2020
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Ingår i: PROCEEDINGS OF THE 2020 DESIGN, AUTOMATION & TEST IN EUROPE CONFERENCE & EXHIBITION (DATE 2020). - 1530-1591. - 9783981926347 ; , s. 169-174
-
Konferensbidrag (refereegranskat)abstract
- The LEGaTO project leverages task-based programming models to provide a software ecosystem for Made in-Europe heterogeneous hardware composed of CPUs, GPUs, FPGAs and dataflow engines. The aim is to attain one order of magnitude energy savings from the edge to the converged cloud/HPC, balanced with the security and resilience challenges. LEGaTO is an ongoing three-year EU H2020 project started in December 2017.
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| 10. |
- Salomonsson, T., et al.
(författare)
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Abnormal cerebral hemodynamics and blood-brain barrier permeability detected with perfusion MRI in systemic lupus erythematosus patients
- 2023
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Ingår i: NeuroImage: Clinical. - : Elsevier BV. - 2213-1582. ; 38
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) has previously shown alterations in cerebral perfusion in patients with systemic lupus erythematosus (SLE). However, the results have been inconsistent, in particular regarding neuropsychiatric (NP) SLE. Thus, we investigated perfusion-based measures in different brain regions in SLE patients with and without NP involvement, and additionally, in white matter hyperintensities (WMHs), the most common MRI pathology in SLE patients. Materials and methods: We included 3 T MRI images (conventional and DSC) from 64 female SLE patients and 19 healthy controls (HC). Three different NPSLE attribution models were used: the Systemic Lupus International Collaborating Clinics (SLICC) A model (13 patients), the SLICC B model (19 patients), and the American College of Rheumatology (ACR) case definitions for NPSLE (38 patients). Normalized cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were calculated in 26 manually drawn regions of interest and compared between SLE patients and HC, and between NPSLE and non-NPSLE patients. Additionally, normalized CBF, CBV and MTT, as well as absolute values of the blood-brain barrier leakage parameter (K2) were investigated in WMHs compared to normal appearing white matter (NAWM) in the SLE patients. Results: After correction for multiple comparisons, the most prevalent finding was a bilateral significant decrease in MTT in SLE patients compared to HC in the hypothalamus, putamen, right posterior thalamus and right anterior insula. Significant decreases in SLE compared to HC were also found for CBF in the pons, and for CBV in the bilateral putamen and posterior thalamus. Significant increases were found for CBF in the posterior corpus callosum and for CBV in the anterior corpus callosum. Similar patterns were found for both NPSLE and non-NPSLE patients for all attributional models compared to HC. However, no significant perfusion differences were revealed between NPSLE and non-NPSLE patients regardless of attribution model. The WMHs in SLE patients showed a significant increase in all perfusion-based metrics (CBF, CBV, MTT and K2) compared to NAWM. Conclusion: Our study revealed perfusion differences in several brain regions in SLE patients compared to HC, independently of NP involvement. Furthermore, increased K2 in WMHs compared to NAWM may indicate blood-brain barrier dysfunction in SLE patients. We conclude that our results show a robust cerebral perfusion, independent from the different NP attribution models, and provide insight into potential BBB dysfunction and altered vascular properties of WMHs in female SLE patients. Despite SLE being most prevalent in females, a generalization of our conclusions should be avoided, and future studies including all sexes are needed.
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| 11. |
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| 12. |
- Svenningstorp, H., et al.
(författare)
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Detection of HC in exhaust gases by an array of MISiC sensors
- 2001
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Ingår i: Sensors and actuators. B, Chemical. - 0925-4005 .- 1873-3077. ; 77:1-2, s. 177-185
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Tidskriftsartikel (refereegranskat)abstract
- Future legislations for car emissions make direct measurements in exhaust gases of hydrocarbon (HC) as well as CO and NOx interesting. Robust sensors that can stand the high temperature and rough environment in the exhaust gases are needed. Silicon carbide has the advantage of being a chemically very inert material, which, due to its high band gap, is a semiconductor even at temperatures around 800°C. Catalytic metal insulator silicon carbide Schottky diode sensors respond to gases like H2, HC, NOx in exhaust gases. The choice of catalytic metal, structure of the metal, and the operation temperature determines the response pattern to different gases. Here we will demonstrate that an array of different MISiC sensors to some extent predicts the HC concentration in gasoline exhaust gases. Chemometric methods are used for the evaluation of the signals. © 2001 Elsevier Science B.V.
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| 13. |
- Waldemarson, AH, et al.
(författare)
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Mycotoxins in laboratory rodent feed
- 2005
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Ingår i: Laboratory animals. - : SAGE Publications. - 0023-6772 .- 1758-1117. ; 39:2, s. 230-235
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Tidskriftsartikel (refereegranskat)abstract
- Twenty-one batches of fixed-formula rodent diets from three feed manufacturers were tested for the presence of five mycotoxins: deoxynivalenol (DON), nivalenol (NIV), HT-2 toxin, T-2 toxin and ochratoxin A (OTA). Five batches were also tested for the presence of zearalenone (ZEN) and six batches for aflatoxins. Detectable levels of DON (up to 298 μg/kg), NIV (up to 118 μg/kg), OTA (up to 3.1 μg/kg) or ZEN (up to 26.7 μg/kg) were found in samples from all manufacturers. Three batches contained two (DON or NIV and OTA or ZEN) and one batch contained three (DON, OTA and ZEN) different mycotoxins. Aflatoxins, T-2 and HT-2 were not detected in any of the batches. The concentrations of mycotoxins detected in the feed were low, but indicated that feed ingredients, probably the cereal ingredients, were contaminated by mycotoxins. Since mycotoxins are known to have toxic and/or immunosuppressive effects, non-contaminated ingredients should be used for production of laboratory animal feed. The results imply that an improved quality control of ingredients used for laboratory rodent feed should be implemented.
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| 14. |
- Wingbrant, Helena, et al.
(författare)
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MISiCFET chemical sensors for applications in exhaust gases and flue gases
- 2002
-
Ingår i: Materials Science Forum. - 0255-5476 .- 1662-9752. ; 433-4, s. 953-956
-
Tidskriftsartikel (refereegranskat)abstract
- A chemical gas sensor based on a silicon carbide field effect transistor with a catalytic gate metal has been under development for a number of years. The choice of silicon carbide as the semiconductor material allows the sensor to operate at high temperatures, for more than 6 months in flue gases at 300degreesC and for at least three days at 700degreesC. The chemical inertness of silicon carbide and a buried gate design makes it a suitable sensor technology for applications in corrosive environments such as exhaust gases and flue gases from boilers. The selectivity of the sensor devices is established through the choice of type and structure of the gate metal as well as the operation temperature. In this way NH3 sensors with low cross sensitivity to NOx have been demonstrated as potential sensors for control of selective catalytic reduction (SCR) of NOx by urea injection into diesel exhausts. Here we show that sensors with a porous platinum or iridium gate show different temperature ranges for NH3 detection. The hardness of the silicon carbide makes it for example more resistant to water splash at cold start of a petrol engine than existing technologies, and a sensor which can control the air to fuel ratio, before the exhaust gases are heated, has been demonstrated. Silicon carbide sensors are also tested in flue gases from boilers. Efficient regulation of the combustion in a boiler will decrease fuel consumption and reduce emissions.
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| 15. |
- Wingbrant, Helena, et al.
(författare)
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Using a MISiCFET device as a cold start sensor
- 2003
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Ingår i: Sensors and actuators. B, Chemical. - 0925-4005 .- 1873-3077. ; 63:1-3, s. 295-303
-
Tidskriftsartikel (refereegranskat)abstract
- As a consequence of the formation of water droplets in the car engine at cold start, the fragile ZrO2 λ sensor cannot be heated until the engine is sufficiently warm. A possibility to shorten the time before closed loop λ control would decrease the exhaust emission. As a solution to this problem, the metal insulator silicon carbide field effect transistor (MISiCFET) sensor, which presumably is more thermo shock resistant than the ZrO2 sensor, could be used at cold start. The requirements for a cold start sensor are, among others, sensitivity to λ (air to fuel ratio) close to stochiometry, selectivity to λ and high speed of response. In this communication, the possibility of using the MISiCFET sensor at cold start is treated. The sensor consists of a SiC based MOSFET device with a buried channel design and a catalytic gate metal of 10 nm TaSix and 100 nm Pt. The response depends linearly on λ at 500 °C. The sensitivity of the device has been tested both in artificial atmospheres and in an engine. Two-level factorial designed experiments showed a high selectivity to λ compared to other gases such as CO, hydrocarbons, NOx and H2. The response time was found to be <10 ms at 500 °C when changing from an oxidizing to a reducing atmosphere. The MISiCFET sensor response showed interesting differences in λ stairs when the λ-value was varied by changing the oxygen, hydrogen or CO concentration. The results show that the MISiCFET sensor is a promising choice as a future cold start sensor.
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| 16. |
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| 17. |
- Berglund, Hanna, et al.
(författare)
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p53 stabilisation potentiates [177Lu]Lu-DOTATATE treatment in neuroblastoma xenografts
- 2023
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Ingår i: European Journal of Nuclear Medicine and Molecular Imaging. - : Springer. - 1619-7070 .- 1619-7089.
-
Tidskriftsartikel (refereegranskat)abstract
- PurposeMolecular radiotherapy is a treatment modality that is highly suitable for targeting micrometastases and [177Lu]Lu-DOTATATE is currently being explored as a potential novel treatment option for high-risk neuroblastoma. p53 is a key player in the proapoptotic signalling in response to radiation-induced DNA damage and is therefore a potential target for radiosensitisation.MethodsThis study investigated the use of the p53 stabilising peptide VIP116 and [177Lu]Lu-DOTATATE, either alone or in combination, for treatment of neuroblastoma tumour xenografts in mice. Initially, the uptake of [177Lu]Lu-DOTATATE in the tumours was confirmed, and the efficacy of VIP116 as a monotherapy was evaluated. Subsequently, mice with neuroblastoma tumour xenografts were treated with placebo, VIP116, [177Lu]Lu-DOTATATE or a combination of both agents.ResultsThe results demonstrated that monotherapy with either VIP116 or [177Lu]Lu-DOTATATE significantly prolonged median survival compared to the placebo group (90 and 96.5 days vs. 50.5 days, respectively). Notably, the combination treatment further improved median survival to over 120 days. Furthermore, the combination group exhibited the highest percentage of complete remission, corresponding to a twofold increase compared to the placebo group. Importantly, none of the treatments induced significant nephrotoxicity. Additionally, the therapies affected various molecular targets involved in critical processes such as apoptosis, hypoxia and angiogenesis.ConclusionIn conclusion, the combination of VIP116 and [177Lu]Lu-DOTATATE presents a promising novel treatment approach for neuroblastoma. These findings hold potential to advance research efforts towards a potential cure for this vulnerable patient population.
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| 18. |
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| 19. |
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| 20. |
- Jansson, Johan, et al.
(författare)
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An anisotropic non-linear material model for glass fibre reinforced plastics
- 2018
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Ingår i: Composite structures. - : Elsevier. - 0263-8223 .- 1879-1085. ; 195, s. 93-98
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Tidskriftsartikel (refereegranskat)abstract
- This paper aims to present a methodology to predict the anisotropic and non-linear behaviour of glass fibre reinforced plastics using finite element methods. A material model is implemented in order to remedy the need of multiple material definitions, and to control the local plastic behaviour as a function of the fibre orientation. Injection moulding simulations traditionally provide second order orientation tensors, which are considered together with a homogenization scheme to compute local material properties. However, in the present study, fourth order tensors are used in combination with traditional methods to provide more accurate material properties. The elastic and plastic response of the material model is optimized to fit experimental test data, until simulations and experiments overlap. The proposed material model can support design engineers in making more informed decisions, allowing them to create smarter products without the need of excessive safety factors, leading to reduced component weight and environmental impact.
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| 21. |
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| 22. |
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| 23. |
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| 24. |
- Meisgen, S, et al.
(författare)
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Auxilin is a novel susceptibility gene for congenital heart block which directly impacts fetal heart function
- 2022
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Ingår i: Annals of the rheumatic diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 81:8, s. 1151-1161
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Tidskriftsartikel (refereegranskat)abstract
- Neonatal lupus erythematosus (NLE) may develop after transplacental transfer of maternal autoantibodies with cardiac manifestations (congenital heart block, CHB) including atrioventricular block, atrial and ventricular arrhythmias, and cardiomyopathies. The association with anti-Ro/SSA antibodies is well established, but a recurrence rate of only 12%–16% despite persisting maternal autoantibodies suggests that additional factors are required for CHB development. Here, we identify fetal genetic variants conferring risk of CHB and elucidate their effects on cardiac function.MethodsA genome-wide association study was performed in families with at least one case of CHB. Gene expression was analysed by microarrays, RNA sequencing and PCR and protein expression by western blot, immunohistochemistry, immunofluorescence and flow cytometry. Calcium regulation and connectivity were analysed in primary cardiomyocytes and cells induced from pleuripotent stem cells. Fetal heart performance was analysed by Doppler/echocardiography.ResultsWe identified DNAJC6 as a novel fetal susceptibility gene, with decreased cardiac expression of DNAJC6 associated with the disease risk genotype. We further demonstrate that fetal cardiomyocytes deficient in auxilin, the protein encoded by DNAJC6, have abnormal connectivity and Ca2+ homoeostasis in culture, as well as decreased cell surface expression of the Cav1.3 calcium channel. Doppler echocardiography of auxilin-deficient fetal mice revealed cardiac NLE abnormalities in utero, including abnormal heart rhythm with atrial and ventricular ectopias, as well as a prolonged atrioventricular time intervals.ConclusionsOur study identifies auxilin as the first genetic susceptibility factor in NLE modulating cardiac function, opening new avenues for the development of screening and therapeutic strategies in CHB.
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| 25. |
- Mellström, Dan, 1945, et al.
(författare)
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Proportion and Characteristics of Patients in Sweden Remaining at High Risk of Fracture Despite Prior Treatment
- 2016
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Ingår i: Clinical Therapeutics. - : Elsevier BV. - 0149-2918. ; 38:7, s. 1686-1695
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Fragility fractures axe a clinical consequence of osteoporosis (OP). Evidence suggests however, current OP treatments may be inadequate in reducing fracture risk. The purpose of this study was to estimate the proportion and characteristics of Swedish patients who remain at high risk of fracture after 2 years of treatment, as evidenced by osteoporotic bone mineral density (BMD), a decrease in BMD, or the occurrence of new fractures. Methods: This was a retrospective, descriptive analysis of a subset of participants obtained from a Swedish osteoporosis patient registry from 1991 to 2009. Patients were required to be osteoporotic, to be treatment naive at baseline, to have returned for at least 1 follow-up visit, and to have reported osteoporosis treatment use for >= 2 years after the baseline visit with a BMD T score. Two overlapping cohorts remaining at high risk of fracture were defined using the BMD T score measured after 2 years of treatment from baseline. The osteoporosis cohort comprised patients who remained osteoporotic, whereas the BMD decrease cohort included patients whose total hip or lumbar spine T score decreased by >= 3%. Findings: A total of 3292 osteoporotic patients were identified in the registry, of whom 392 met the study inclusion criteria. The mean (SD) patient age was 68.3 (8.5) years, with most patients being female (92.3%). Among all patients, 297 (75.8%) remained osteoporotic after at least 2 years of treatment, 90 (23.0%) experienced a BMD decrease of >= 3%, and 23 (5.9%) reported an incident fracture between the baseline and first follow-up visit. More than three-quarters (76.8%) of all patients reported taking bisphosphonates, whereas only 72.4% and 47.8% reported this in the osteoporosis and BMD decrease cohorts, respectively. Raloxifene was the only nonbisphosphonate used, with 24.2% of all patients reportedly taking it. Implications: This study highlighted that despite 2 years of osteoporosis treatment, a high percentage of patients remain at high risk of fracture. There is a need for improved treatment strategies that reduce fracture risk and improve patient outcomes in the real-world setting.
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| 26. |
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| 27. |
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| 28. |
- Sagalowicz, L., et al.
(författare)
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Defects, structure, and chemistry of InP-GaAs interfaces obtained by wafer bonding
- 2000
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 87:9, s. 4135-4146
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Tidskriftsartikel (refereegranskat)abstract
- We have examined the crystallographic structure of GaAs/InP interfaces obtained by wafer fusion following different procedures. Plan-view and cross-sectional transmission electron microscopy reveal that the interface is not only composed of a regular array of two sets of edge dislocations and is more complex than generally supposed. If a twist is created due to misalignment of the two substrates, the dislocations are not edge dislocations but also have a screw component. Dislocations for which the Burgers vectors have a component normal to the interface are also present. Those dislocations probably result from steps and some of them accommodate the tilt between the two substrates. Inclusions and voids as well as a low number of volume dislocations are present in all the samples. The observed volume dislocation density near the interface lies in the 10(5)-10(7) cm(-2) range and these volume dislocations may be associated with thermal mismatch. The origin of all these defects is discussed.
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| 29. |
- Salomonsson, P., et al.
(författare)
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Temperature-dependent performance of 1.55 ÎŒm vertical-cavity lasers with InGaAsP/InP bottom mirror
- 1999
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Ingår i: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. - Davos, Switz. ; :Piscataway, NJ, United States, s. 223-226
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Tidskriftsartikel (refereegranskat)abstract
- We have fabricated and evaluated a long-wavelength vertical-cavity laser (VCL) based on an epitaxially integrated InP distributed Bragg reflector (DBR) under continuous wave (CW) and pulsed conditions. We conclude that, for an InP-DBR-down configuration, the high-temperature performance is limited by the heat conductivity of the bottom mirror. The highest operating temperature for CW and pulsed condition is 17 °C and 101 °C respectively, indicating a substantial self-heating for CW. To investigate the prospect for improved performance in other mounting configurations, we have applied a two-dimensional finite element analysis to the heat transfer problem. It is suggested that for top-side-down mounting with the AlGaAs/GaAs DBR closest to the heat sink, a performance comparable to that of so called double-fused VCLs could be possible.
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| 30. |
- Salomonsson, S, et al.
(författare)
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A serologic marker for fetal risk of congenital heart block
- 2002
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 1529-0131 .- 0004-3591. ; 46:5, s. 1233-1241
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To analyze the Immoral immune response to Ro/SSA and La/SSB antigens in detail, in order to identify markers in mothers at high risk of having children with congenital heart block (CHB). Methods. Serum samples were obtained from 9 Ro/La-positive mothers who gave birth to affected children, from their 8 newborns with CHB, and from 26 Ro/La-positive mothers whose children were healthy. Antibodies against Ro 52-kd, Ro 60-kd, and La were analyzed by enzyme-linked inummosorbent assay and immunoblotting, using recombinant proteins and synthetic peptides. Results. IgG anti-Ro 52-kd antibodies were detected in all mothers who gave birth to children with CHB, as well as in their affected children, but were less frequent and at lower levels in control mothers. Fine mapping revealed a striking difference in which the response in mothers with affected children was dominated by antibodies to amino acids 200-239 of the Ro 52-kd protein (P = 0.0002), whereas the primary activity in control mothers was against amino acids 176-196 (P = 0.001). Furthermore, 8 of 9 mothers of children with CHB had antibody reactivity against amino acids 1-135 of the Ro 52-kd protein, containing 2 putative zinc ringers reconstituted under reducing conditions. Conclusion. The results suggest that development of CHB is strongly dependent on a specific antibody profile to Ro 52-kd, which may be a useful tool to identify pregnant Ro/La-positive women at risk of delivering a baby with CHB. Close monitoring of mothers at high risk would enable early detection of a block that is still developing and allow early treatment to combat more serious complications.
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| 31. |
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| 32. |
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| 33. |
- Strand, V, et al.
(författare)
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Immediate and delayed effects of nitrogen dioxide exposure at an ambient level on bronchial responsiveness to histamine in subjects with asthma
- 1996
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Ingår i: The European respiratory journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 9:4, s. 733-740
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Tidskriftsartikel (refereegranskat)abstract
- The time-kinetics of NO2 induced effects on bronchial responsiveness are poorly known as most observations have been made shortly after exposure. The aim of this study was to measure nonspecific bronchial responsiveness, lung function and inflammatory markers at different times after NO2 exposure in asthmatics. Nineteen subjects with mild asthma were exposed to either purified air or 488 micrograms.m-3 (0.26 ppm) NO2 for 30 min during intermittent exercise. Airway responsiveness to histamine, specific airway resistance (sRaw) and thoracic gas volume (TGV) were measured 30 min, 5 h, 27 h and 7 days after exposure. Peripheral blood inflammatory mediators and the expression of an adhesion molecule, (Mac1) on granulocytes, were analysed 30 min and 27 h after exposure. Bronchial responsiveness to histamine was significantly increased 5 h after NO2 exposure when compared to air (median provocative dose of histamine required to cause 100% increase of sRaw ((PDsRaw,100%) 110 micrograms after NO2 exposure vs 203 micrograms on air). There was a tendency for an increase after 30 min, which was nonsignificant (median PDsRaw,100% 100 vs 153 micrograms). NO2 exposure did not affect sRaw, but TGV was significantly reduced after exposure. We found an increased expression of Mac-1 on granulocytes 30 min after NO2 exposure when compared to pre-exposure values. No effect was seen on tryptase, eosinophil cationic protein (ECP), or myeloperoxidase (MPO). These results suggest that exposure to an ambient level of NO2 causes a delayed effect on bronchial responsiveness in asthmatics. The increased expression of an adhesion molecule in peripheral blood may indicate a NO2-induced priming of human granulocytes.
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| 34. |
- Streubel, K., et al.
(författare)
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Novel technologies for 1.55-mu m vertical cavity lasers
- 2000
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Ingår i: Optical Engineering. - : SPIE-Intl Soc Optical Eng. - 0091-3286 .- 1560-2303. ; 39:2, s. 488-497
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Tidskriftsartikel (refereegranskat)abstract
- We report on three novel vertical-cavity laser (VCL) structures for 1.55-mu m operation. Two of the structures utilize an n-type GalnAsP/InP Bragg mirror combined with an Al(Ga)As/GaAs mirror using either wafer fusion or metamorphic epitaxial growth. The third employs two wafer-fused AlGaAs/GaAs mirrors, in which lateral current confinement is obtained by localized fusion of the p mirror. Ali three VCLs use strained GalnAsP quantum welts as active material and achieve continuous-wave (cw) operation at room temperature or above. The single fused VCL operates up to 17 and 101 degrees C in continuous-wave and pulsed mode, respectively. The monolithic VCL-structure with a metamorphic GaAs/AlAs n-type mirror uses a reverse-biased tunnel junction for current injection. This laser achieves record high output power (1 mW) at room temperature and operates cw up to 45 degrees C. The double fused VCLs with a 10x10-mu m(2) active area operate cw up to 30 degrees C with threshold current as low as 2.5 mA and series resistance of 30 Omega. The emission spectra exhibit a single lasing mode polarized with 30-dB extinction ratio and a spectral linewidth of 150 MHz.
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| 35. |
- Unéus, Lars, et al.
(författare)
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Schottky diodes with thin catalytic gate metals for potential use as ammonia sensors for exhaust gases
- 1999
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Ingår i: Sensors and materials. - : Scientific Publishing Division Myu. - 0914-4935. ; 11:5, s. 305-318
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Tidskriftsartikel (refereegranskat)abstract
- Selective catalytic reduction (SCR) is a method in which ammonia reacts with nitric oxides in a catalytic converter to form water and nitrogen. We show that catalytic Metal Insulator Silicon Carbide (MISiC) devices can be used as ammonia sensors for a SCR system in a diesel engine. Different catalytic metals, Pt and Ir, with a thickness of 30 or 50 nm were investigated. The temperature dependence of the ammonia response of the sensors was characterized. Maximum responses were found at temperatures between 225-250 degrees C. Preliminary experiments were performed to investigate how annealing in different gas ambient influences the response-temperature curve of the sensors. In synthetic diesel exhausts with ammonia added, the sensors showed very good selectivity for ammonia and a small interaction effect with oxygen. The influence of other gas components was almost negligible. Temperature in the diesel exhaust system can reach 550 degrees C; however, operating at temperatures above 400 degrees C limited the lifetime of the sensor. Anger electron spectroscopy (AES) revealed that island formation of the metal due to structural changes was the main reason for failure of the sensor.
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