19 results on '"Andersen, Steen"'
Search Results
2. Development and validation of a reversed-phase liquid chromatographic method for analysis of degradation products of estradiol in Vagifem ® tablets
- Author
-
Nygaard, Lars, Drøhse Kilde, Helle, Andersen, Steen G, Henriksen, Lars, and Overby, Vivi
- Published
- 2004
- Full Text
- View/download PDF
3. Tubular markers do not predict the decline in glomerular filtration rate in type 1 diabetic patients with overt nephropathy.
- Author
-
Nielsen, Stine E., Andersen, Steen, Zdunek, Dietmar, Hess, Georg, Parving, Hans-Henrik, and Rossing, Peter
- Subjects
- *
KIDNEY diseases , *KIDNEY glomerulus , *GLOMERULAR filtration rate , *DIABETES , *DIABETIC nephropathies - Abstract
Recent studies have shown that both glomerular and tubulointerstitial damage are important factors in the pathophysiology and progression of diabetic nephropathy. To examine whether markers of tubular damage are useful in monitoring the progression of disease, we measured urinary levels of neutrophil gelatinase-associated lipocalin (NGAL), liver-fatty acid-binding protein (LFABP), and kidney injury molecule-1 (KIM-1) in a 3-year intervention study of 63 type 1 diabetic patients with kidney disease. The baseline mean glomerular filtration rate (GFR) was 87 ml/min per 1.73 m2 and urinary albumin excretion 1141 mg/24 h. Patients with the highest compared with the lowest quartile of urinary NGAL at baseline had higher urinary KIM-1 levels and a significant decrease in their GFR each year. Using linear regression analysis, we found that elevated urinary NGAL and KIM-1 concentrations were associated with a faster decline in GFR, but not after adjustment for known promoters of progression. Urinary LFABP was not related to decline in GFR. Losartan treatment (100 mg/day) reduced urinary KIM-1 by 43% over a 12-month period. Thus, urine biomarker measurements in patients with type 1 diabetic nephropathy did not provide additional prognostic information to that of known progression promoters. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
4. Reduction of urinary connective tissue growth factor by Losartan in type 1 patients with diabetic nephropathy.
- Author
-
Andersen, Steen, van Nieuwenhoven, Frans A., Tarnow, Lise, Rossing, Peter, Rossing, Kasper, Wieten, Lotte, Goldschmeding, Roel, and Parving, Hans-Henrik
- Subjects
- *
KIDNEY diseases , *GROWTH factors , *TISSUES , *DIABETES , *DIABETIC nephropathies , *MEDICAL research , *PROTEINS , *GLOMERULAR filtration rate , *CONNECTIVE tissue growth factor , *CONFIDENCE intervals , *TYPE 1 diabetes , *TREATMENT effectiveness , *ENZYME-linked immunosorbent assay , *DESCRIPTIVE statistics , *LOSARTAN , *FOCAL segmental glomerulosclerosis , *LONGITUDINAL method , *ALBUMINURIA , *PHARMACODYNAMICS - Abstract
Reduction of urinary connective tissue growth factor by Losartan in type 1 patients with diabetic nephropathy.Background.Connective tissue growth factor (CTGF) is an important profibrotic cytokine implicated in development of diabetic glomerulosclerosis. Urinary CTGF is reported to be significantly increased in patients with diabetic nephropathy. The present study aimed to investigate the short- and long term effects of angiotensin II receptor blockade by Losartan on urinary CTGF levels in hypertensive type 1 diabetic patients with diabetic nephropathy.Methods.Seventy-one hypertensive type 1 diabetic patients with diabetic nephropathy were included in the study. After a washout period of 4 weeks, the patients received Losartan 50 mg, 100 mg, and 150 mg once daily in treatment periods each lasting 2 months. Thereafter, patients were followed prospectively during treatment with Losartan 100 mg o.d. with a total mean follow-up time of 36 months. At baseline, after 2, 4, and 6 months and then biannually, urinary and plasma CTGF levels[enzyme linked immunosorbent assay (ELISA) fibroGen], albuminuria (Turbidimetry), glomerular filtration rate (GFR)[51-creatinine ethylenediaminetetraacetic acid (51Cr-EDTA plasma clearance)] and 24 hours blood pressure (TM2420)) were determined.Results.Baseline levels of urinary and plasma CTGF were 7076 (5708 to 8770) ng/24 hours[geometric mean (95% CI)] and 12.7 (7.3) ng/mL[mean (SD)], respectively. Albuminuria, GFR, and arterial blood pressure at baseline were 1152 (937 to 1416) mg/24 hours, 88 (24) mL/min/1.73 m2, and 153/80 (17/9) mm Hg, respectively. Losartan significantly reduced urinary CTGF by 21% (9 to 31) (95% CI) initially (P<0.05 vs. baseline), with no further reduction after increasing dose. The sustained reduction in urinary CTGF was 22% (12 to 32) (P<0.05 vs. baseline). Rate of decline in GFR during the study was 3.2 (−1.6 to 15.9) mL/min/year[median (range)]. Reduction in urinary CTGF was correlated with a lower rate of decline in GFR (r= 0.23,P= 0.05). Plasma CTGF remained unchanged throughout the study.Conclusion.Our 3-year study demonstrates that Losartan persistently reduces urinary CTGF excretion, which is associated with a slower rate of decline in GFR. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
5. Renoprotection with and without blood pressure reduction.
- Author
-
Laverman, Gozewijn Dirk, Andersen, Steen, Rossing, Peter, Navis, Gerjan, De Zeeuw, Dick, and Parving, Hans-Henrik
- Subjects
- *
BLOOD pressure , *ALBUMINURIA , *PROTEINURIA , *DIABETES - Abstract
Renoprotection with and without blood pressure reduction. AT1-receptor blockade dose dependently lowers blood pressure (BP) and albuminuria. Reduction of BP and albuminuria are independent treatment targets for renoprotection, but whether this requires similar dose titration is unknown. We tested this in two studies designed to find the optimal antialbuminuric dose of losartan in type 1 diabetic (DM, N = 50) and nondiabetic renal patients (ND, N = 12). After baseline, treatment followed with losartan 50, 100, and 150 mg/day, each dose for eight (DM) or six weeks (ND). At the end of each period, albuminuria (24-hour samples) and mean arterial pressure (MAP) were measured. Patients were divided into "good" and "poor" BP responders (BP+, BP-) according to BP response above or below group median. Baseline MAP in the BP- groups was 102 (97, 104) mm Hg in DM (median, 95% CI) and 91 (80, 108) mm Hg in ND. The top of the dose response for BP (obtained at losartan 100 mg) in the BP- groups was -2 (-4, 3) mm Hg in DM and –1 (-6, 2) mm Hg in ND, versus -15 (-18, -12) mm Hg and -16 (-26, -18) mm Hg in BP+ groups (both P < 0.05). Albuminuria was reduced dose dependently both in BP- and BP+: with 100 mg, the reduction in albuminuria in DM BP- was -32% (-49, 13) versus -45% (-60, -38) in DM BP+ and -45% (-70,-7) versus –25% (-58, -6) in ND BP- and BP+ (all P > 0.05). Moreover, in patients in whom BP fell below the recommended treatment target of 130/80 mm Hg (13 in DM and 10 in ND), albuminuria was progressively reduced, with further increasing the dose of losartan in most patients. Absence of BP response to losartan does not preclude a reduction in albuminuria, and optimal reduction of albuminuria may require titration beyond the predefined BP target. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
6. Dual blockade of the renin-angiotensin system versus maximal recommended dose of ACE inhibition in diabetic nephropathy.
- Author
-
Jacobsen, Peter, Andersen, Steen, Rossing, Kasper, Jensen, Berit R., and Parving, Hans-Henrik
- Subjects
- *
RENIN-angiotensin system , *ACE inhibitors , *DIABETIC nephropathies , *ALBUMINURIA , *BIPHENYL compounds , *BLOOD pressure , *COMBINATION drug therapy , *COMPARATIVE studies , *CROSSOVER trials , *DRUG synergism , *HETEROCYCLIC compounds , *ANTIHYPERTENSIVE agents , *TYPE 1 diabetes , *RESEARCH methodology , *MEDICAL cooperation , *RESEARCH , *STATISTICAL sampling , *EVALUATION research , *RANDOMIZED controlled trials , *BLIND experiment , *ENALAPRIL , *DISEASE complications - Abstract
Background: Albuminuria and hypertension are predictors of poor renal and cardiovascular outcome in diabetic patients. We tested whether dual blockade of the renin-angiotensin system (RAS) with both an angiotensin-converting enzyme (ACE) inhibitor and an angiotensin II receptor blocker (ARB) is superior to maximal recommended dose of ACE inhibitor in type 1 diabetic patients with diabetic nephropathy (DN).Methods: We performed a randomized, double-blind, crossover trial with 8 weeks treatment with placebo and irbesartan 300 mg (once daily), added on top of enalapril 40 mg (once daily). We included 24 type 1 patients with DN. At the end of each treatment period, albuminuria, 24-hour blood pressure, and glomerular filtration rate (GFR) were measured.Results: Values on ACE inhibitors + placebo were: albuminuria [mean (95% CI)], 519 (342 to 789) mg/24 hours; blood pressure [mean (SEM)], 131 (3)/74 (1) mm Hg, and GFR [mean (SEM)], 65 (5) mL/min/1.73 m2. Dual blockade of the RAS induced a reduction in albuminuria [mean (95% CI)] of 25% (15, 34) (P < 0.001), a reduction in systolic blood pressure of 8 mm Hg (4, 12) (P = 0.002), and a reduction of 4 mm Hg (2, 7) (P = 0.003) in diastolic blood pressure. GFR and plasma potassium remained unchanged during both treatment regimes. Dual blockade was safe and well tolerated.Conclusion: Dual blockade of the RAS is superior to maximal recommended dose of ACE inhibitors with regard to lowering of albuminuria and blood pressure in type 1 patients with DN. Long-term trials are needed to further establish the role of dual blockade of the RAS in renal and cardiovascular protection. [ABSTRACT FROM AUTHOR]- Published
- 2003
- Full Text
- View/download PDF
7. Renoprotective effects of losartan in diabetic nephropathy: Interaction with ACE insertion/deletion genotype?
- Author
-
Andersen, Steen, Tarnow, Lise, Cambien, Francois, Rossing, Peter, Juhl, Tina R., Deinum, Jaap, and Parving, Hans-Henrik
- Subjects
- *
ANGIOTENSIN converting enzyme , *DIABETIC nephropathies , *ALBUMINURIA , *DIABETES , *GENETICS , *THERAPEUTICS - Abstract
Renoprotective effects of losartan in diabetic nephropathy: Interaction with ACE insertion/deletion genotype? Background. The beneficial short- and long-term renoprotective effects of angiotensin I-converting enzyme (ACE) inhibition are lower in albuminuric diabetic patients homozygous for the deletion compared to the insertion polymorphism of the ACE gene. In an attempt to overcome this interaction, we evaluated the short-term renoprotective effect in diabetic nephropathy of the angiotensin II receptor antagonist losartan in patients homozygous for the insertion or the deletion allele. Methods. Fifty-four hypertensive type 1 diabetic patients with diabetic nephropathy homozygous for the insertion (I; N = 26) or the deletion (D; N = 28) allele of the ACE/ID polymorphism were included. After four weeks of washout, the patients received losartan 50 mg daily followed by 100 mg in two treatment periods each lasting two months. Patients and investigators were blinded to ACE genotypes. At baseline and in the end of the treatment periods, 24-hour blood pressure, albuminuria and glomerular filtration rate values were determined. Results. At baseline, blood pressure, albuminuria and glomerular filtration rate (GFR) values were similar in the two genotype groups [II vs. DD, 1134 (238 to 5302) vs. 1451 (227 to 8129) mg/24 h, median (range); 156/82 (17/9) vs. 153/80 (17/11) mm Hg, mean (SD); and 86 (22) vs. 88 (24) mL/min/1.73 m2 , respectively]. Both doses of losartan significantly lowered blood pressure, albuminuria, and GFR (P < 0.05 vs. baseline). Losartan 100 mg was more effective than 50 mg in reducing albuminuria, 51% (95% CI; 40 to 61) versus 33% (23 to 42), respectively (P < 0.01). No differences in the impact of losartan between the II and DD groups were observed: Losartan 100 mg lowered systolic/diastolic blood pressure by 12/6 and 10/4 mm Hg, whereas albuminuria decreased by 55% (35 to 68) and 46% (28 to 61), in the II and DD groups, respectively (P =... [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
8. Glomerular permselectivity in early stages of overt diabetic nephropathy.
- Author
-
Andersen, Steen, Blouch, Kristina, Bialek, Joan, Deckert, Marja, Parving, Hans-Henrik, and Myers, Bryan D.
- Subjects
- *
DIABETIC neuropathies , *ALBUMINURIA , *PATHOLOGICAL physiology - Abstract
Studies the glomerular permselectivity in early stages of overt diabetic neuropathy. Development of pathological levels of albuminuria; Neutralization of negatively charged electrostatic barrier within the glomerular capillary wall; Basis of an albumin excretion rate.
- Published
- 2000
- Full Text
- View/download PDF
9. Role of patient factors in therapy resistance to antiproteinuric intervention in nondiabetic and diabetic nephropathy.
- Author
-
Bos, Hendrik, Andersen, Steen, Rossing, Peter, De Zeeuw, Dick, Parving, Hans-Henrik, De Jong, Paul E., and Navis, Gerjan
- Subjects
- *
KIDNEY diseases , *THERAPEUTICS , *NEPHROLOGY - Abstract
Role of patient factors in therapy resistance to antiproteinuric intervention in nondiabetic and diabetic nephropathy. Reduction of proteinuria is a prerequisite for successful long-term renoprotection. To investigate whether individual patient factors are determinants of antiproteinuric efficacy, we analyzed individual responses to different modes of antiproteinuric intervention in nondiabetic and diabetic patients, obtained in prior studies comparing the efficacy of various pharmacological regimens. The individual antiproteinuric response to angiotensin-converting enzyme (ACE) inhibition positively correlated to the response to angiotensin type I (AT1) receptor blockade in diabetic (r = 0.67, P < 0.01, N = 16) as well as nondiabetic patients (r = 0.75, P < 0.01, N = 12). This corresponded to the correlations for antihypertensive efficacy between ACE inhibition and AT1 receptor blockade in diabetic (r = 0.73, P < 0.001) as well as nondiabetic patients (r = 0.55, P < 0.05). Remarkably, the antiproteinuric response to ACE inhibition also correlated positively to the antiproteinuric response to indomethacin (r = 0.63, P < 0.05, N = 9). Thus, patients responding favorably to one class of antiproteinuric drugs also respond favorably to other classes of available drugs, supporting a main role for individual patient factors in responsiveness or resistance to antiproteinuric intervention. In the search for strategies to improve response in these high risk patients, combination-treatment (combining different drugs, and combining drugs with dietary measures like sodium and protein restriction), and the use of higher doses may provide more fruitful strategies to optimize renoprotection than shifting to other classes of the available drugs. [ABSTRACT FROM AUTHOR]
- Published
- 2000
- Full Text
- View/download PDF
10. Renoprotective effects of angiotensin II receptor blockade in type 1 diabetic patients with diabetic nephropathy.
- Author
-
Andersen, Steen, Tarnow, Lise, Rossing, Peter, Hansen, Birgitte V., and Parving, Hans-Henrik
- Subjects
- *
ANGIOTENSIN II , *DIABETIC neuropathies , *BRADYKININ , *GLOMERULAR filtration rate - Abstract
Renoprotective effects of angiotensin II receptor blockade in type 1 diabetic patients with diabetic nephropathy. Background. Angiotensin I-converting enzyme (ACE) inhibitors reduce angiotensin II formation and induce bradykinin accumulation. Animal studies suggest that bradykinin may play a role for the effects of ACE inhibition on blood pressure and kidney function. Therefore, we compared the renal and hemodynamic effects of specific intervention in the renin-angiotensin system by blockade of the angiotensin II subtype-1 receptor to the effect of ACE inhibition. Methods. A randomized, double-blind, cross-over trial was performed in 16 type 1 diabetic patients (10 men), age 42 ± 2 years (mean ± sem). The study consisted of five periods, each lasting two months. The patients received losartan 50 mg, losartan 100 mg, enalapril 10 mg, enalapril 20 mg, and placebo in random order. At the end of each period, albuminuria, 24-hour blood pressure, and glomerular filtration rate (GFR) were determined. Results. Both doses of losartan and enalapril reduced albuminuria (P < 0.05) and mean arterial blood pressure (MABP; P < 0.05), whereas GFR remained stable. Albuminuria was reduced by 33% (95% CI, 12 to 51) on losartan 50 mg, 44% (95% CI, 26 to 57) on losartan 100 mg, 45% (95% CI, 23 to 61) on enalapril 10 mg, and 59% (95% CI, 39 to 72) on enalapril 20 mg, and MABP fell by 9 ± 2, 8 ± 2, 6 ± 3, and 11 ± 3 mm Hg (mean ± sem), respectively. No significant differences were found between the effects of losartan 100 mg and enalapril 20 mg. HbA1C and sodium intake remained unchanged throughout the study, whereas a significant rise in serum potassium occurred during ACE inhibition. Conclusion. The angiotensin II subtype 1 receptor antagonist, losartan, reduces albuminuria and MABP similar to the effect of ACE inhibition. These results indicate that the reduction in albuminuria and blood pressure during ACE inhibition is primarily... [ABSTRACT FROM AUTHOR]
- Published
- 2000
- Full Text
- View/download PDF
11. Solid state electrolyte membranes for direct methanol fuel cells
- Author
-
Kjær, Jørgen, Yde-Andersen, Steen, Knudsen, Niels A., and Skou, Eivind
- Published
- 1991
- Full Text
- View/download PDF
12. Properties of nasicon electrolytes prepared from alkoxide derived gels: Ionic conductivity, durability in molten sodium and strength test data
- Author
-
Yde-Andersen, Steen, Lundsgaard, Jørgen S., Møller, Lone, and Engell, John
- Published
- 1984
- Full Text
- View/download PDF
13. The opioid ketobemidone has a NMDA blocking effect
- Author
-
Andersen, Steen, Dickenson, Anthony H., Kohn, Michelle, Reeve, Alison, Rahman, Wahida, and Ebert, Bjarke
- Published
- 1996
- Full Text
- View/download PDF
14. Development and validation of a reversed-phase liquid chromatographic method for analysis of degradation products of estradiol in Vagifem® tablets
- Author
-
Nygaard, Lars, Drøhse Kilde, Helle, Andersen, Steen G., Henriksen, Lars, and Overby, Vivi
- Subjects
- *
ESTRADIOL , *DRUG tablets , *CHROMATOGRAPHIC analysis , *PLACEBOS - Abstract
A stability-indicating liquid chromatographic method for the determination of degradation products and impurities in Vagifem®, estradiol vaginal tablets has been developed and validated. Vagifem® is a low dose preparation containing only 25 μg 17β-estradiol in a tablet matrix of 80 mg (a drug to excipient ratio of 1:3200). This paper presents the rationale for the optimization of the sample preparation in order to minimize placebo interference as well as validation data for linearity, accuracy, precision, ruggedness, specificity and limits of detection and quantification. Data shows that the method is suitable for routine analysis of minute amounts of estradiol impurities. [Copyright &y& Elsevier]
- Published
- 2004
- Full Text
- View/download PDF
15. Breakthrough Cancer Pain: An Observational Study of 1000 European Oncology Patients.
- Author
-
Davies, Andrew, Buchanan, Alison, Zeppetella, Giovambattista, Porta-Sales, Josep, Likar, Rudolf, Weismayr, Wolfgang, Slama, Ondrej, Korhonen, Tarja, Filbet, Marilene, Poulain, Philippe, Mystakidou, Kyriaki, Ardavanis, Alexandros, O’Brien, Tony, Wilkinson, Pauline, Caraceni, Augusto, Zucco, Furio, Zuurmond, Wouter, Andersen, Steen, Damkier, Anette, and Vejlgaard, Tove
- Subjects
- *
CANCER pain , *SCIENTIFIC observation , *CANCER patients , *EUROPEANS , *PHARMACOLOGY , *ONCOLOGY , *DISEASES - Abstract
Abstract: Context: Breakthrough pain is common in patients with cancer and is a significant cause of morbidity in this group of patients. Objectives: The aim of this study was to characterize breakthrough pain in a diverse population of cancer patients. Methods: The study involved 1000 cancer patients from 13 European countries. Patients were screened for breakthrough pain using a recommended diagnostic algorithm and then questioned about the characteristics and management of their pain. Results: Of the 1000 patients, 44% reported incident pain, 41.5% spontaneous pain, and 14.5% a combination. The median number of episodes was three a day. The median time to peak intensity was 10 minutes, with the median for patients with incident pain being five minutes (P < 0.001). The median duration of untreated episodes was 60 minutes, with the median for patients with incident pain being 45 minutes (P = 0.001). Eight hundred six patients stated that pain stopped them doing something, 66 that it sometimes stopped them doing something, and only 107 that it did not interfere with their activities. Patients with incident pain reported more interference with walking ability and normal work, whereas patients with spontaneous pain reported more interference with mood and sleep. As well, 65.5% of patients could identify an intervention that improved their pain (29.5%, pharmacological; 23%, nonpharmacological; 12%, combination). Regarding medications, 980 patients were receiving an opioid to treat their pain, although only 191 patients were receiving a transmucosal fentanyl product licensed for the treatment of breakthrough pain. Conclusion: Breakthrough cancer pain is an extremely heterogeneous condition. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
16. Fuel cell climatic tests designed for new configured aircraft application
- Author
-
Bégot, Sylvie, Harel, Fabien, Candusso, Denis, François, Xavier, Péra, Marie-Cécile, and Yde-Andersen, Steen
- Subjects
- *
PROTON exchange membrane fuel cells , *CLIMATOLOGY , *TRANSPORTATION , *LOW temperatures , *INFORMATION theory , *AIRPLANES - Abstract
Abstract: The implementation of Fuel Cell (FC) systems in transportation systems, as aircrafts, requires some better understanding and mastering of the new generator behaviours in low temperature environments. To this end, a PEMFC stack is tested and characterised in a climatic chamber. The impacts of the low temperatures over different FC operation and start-up conditions are estimated using a specific test bench developed in-lab. Some descriptions concerning the test facilities and the experimental set-up are given in the paper, as well as some information about the test procedures applied. Some examples of test results are shown and analysed. The experiments are derived from aircraft requirements and are related with different scenarios of airplane operation. Finally, some assessments concerning the FC system behaviour in low temperature conditions are made, especially with regard to the constraints to be encountered by the next embedded FC generators. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
- View/download PDF
17. A study of metal concentrations and metallothionein binding capacity in liver, kidney and brain tissues of three Arctic seal species
- Author
-
Sonne, Christian, Aspholm, Ole, Dietz, Rune, Andersen, Steen, Berntssen, Marc H.G., and Hylland, Ketil
- Subjects
- *
METALLOTHIONEIN , *PHYSIOLOGICAL effects of heavy metals , *HEAVY metal toxicology , *TISSUE analysis , *SEALS (Animals) , *ANIMAL species , *BIOACCUMULATION , *CARRIER proteins , *BINDING sites - Abstract
Abstract: Arctic seals are known to accumulate relatively high concentrations of potential toxic heavy metals in their vital organs, such as livers and kidneys, as well as in their central nervous system. We therefore decided to determine whether mercury, copper, cadmium and zinc levels in liver, kidney and brain tissues of three Arctic seal species were associated with the intracellular metal-binding protein metallothionein (MT) as a sign of toxic exposure. Samples from four ringed (Phoca hispida), five harp (P . groenlandica) and five hooded (Cystophora cristata) seals taken during field trips to Central West Greenland (Godhavn) and the Barents Sea in the spring of 1999 were used for the present study. In all three seal species concentrations of mercury, zinc and copper were highest in the liver, except for cadmium which was highest in the kidneys. Metal concentrations increased significantly in the order: ringed seal
- Published
- 2009
- Full Text
- View/download PDF
18. Mechanical behaviour of a fuel cell stack under vibrating conditions linked to aircraft applications part I: Experimental
- Author
-
Rouss, Vicky, Lesage, Philippe, Bégot, Sylvie, Candusso, Denis, Charon, Willy, Harel, Fabien, François, Xavier, Selinger, Viktor, Schilo, Christine, and Yde-Andersen, Steen
- Subjects
- *
PROTON exchange membrane fuel cells , *MECHANICAL behavior of materials , *AIRPLANES , *VIBRATION (Aeronautics) , *ACCELEROMETERS , *ACCELERATION (Mechanics) - Abstract
Abstract: The implementation of fuel cells (FC) in transportation systems, as airplanes, requires some better understanding and mastering of their mechanical behaviours in vibrating environments. To this end, a FC stack is tested on a vibrating platform and characterised on the three geometric axes of the equipment. The impacts over the stack assembly of sine excitations with different frequencies and magnitudes are estimated using various accelerometers placed on different locations of the FC surface. Leak checks are also performed in order to verify that no malfunctions occur in the stack. In this first part, some descriptions concerning the test facilities and the experimental setup are given, as well as some information about the mechanical test procedure applied. Some frequency – acceleration diagrams resulting from the experiments are shown and analysed. Finally, some assessments concerning the stack behaviour in vibrating conditions are made. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
- View/download PDF
19. Does the nutrition profile of vitamins, fatty acids and microelements counteract the negative impact from organohalogen pollutants on bone mineral density in Greenland sledge dogs (Canis familiaris)?
- Author
-
Sonne, Christian, Rigét, Frank F., Beck Jensen, Jens-Erik, Hyldstrup, Lars, Teilmann, Jenni, Dietz, Rune, Kirkegaard, Maja, Andersen, Steen, Letcher, Robert J., and Jakobsen, Jette
- Subjects
- *
SLED dogs , *ORGANOHALOGEN compounds , *POLYCHLORINATED biphenyls , *PEST control - Abstract
Abstract: There is a great need for understanding the impact from dietary OHCs (organohalogen compounds) on bone mineral composition – and thereby osteoporosis – in especially arctic wildlife such as polar bears (Ursus maritimus) as well as humans. For that purpose, we measured BMD (bone mineral density) by DXA scanning (g/cm−2) in 15 age and weight normalized sledge dog (Canis familiaris) bitches and their 26 pups divided into a control group (n =26) given 50–200 g/day clean pork (Suis scrofa) fat and a treated group (n =15) given 50–200 g/day OHC polluted minke whale (Balaenoptera acutorostrata) blubber as main lipid sources. The results showed that BMD increased significantly with age (linear regression: p <0.0001, r 2 =0.83, n =41) while no sex difference was found in the F-generation (two-way ANOVA: all p >0.3). No differences in BMDfemur or BMDvertebrae between exposed and control individuals in the bitch generation were found (linear mixed effect model: both p >0.38). Likewise, no difference between exposed and control subadults and juveniles in the F-generation was found (two-way ANOVA: all p >0.33). Correlation analyses between BMDfemur, BMDvertebrae and groups of OHCs, respectively, did not show any statistically significant relationships nor a clear or decreasing trend (Pearson''s: p: 0.07–0.78; r: −0.2–0.59; n: 10–18). As the groups were similar regarding genetics, age and sex are the only factors that can explain this observation. Either the pollutants did not have an impact on BMD using the present time frame and OHC concentrations (threshold levels not reached), or the difference in food composition (mainly vitamins and n3 fatty acids) conceal the potential OHC impact on BMD. Such information is important when evaluating the positive and negative health consequences from eating polluted marine species. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.