| 1. |
- Estanqueiro, A., et al.
(författare)
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Energy storage for wind integration : Hydropower and other contributions
- 2012
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Ingår i: Power and Energy Society General Meeting, 2012 IEEE. - : IEEE. - 9781467327275 ; , s. 6344652-
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Konferensbidrag (refereegranskat)abstract
- The amount of wind power and other timevariable non-dispatchable renewable energy sources (RES) is rapidly increasing in the world. A few power systems are already facing very high penetrations from variable renewables which can surpass the systems' consumption during no-load periods, requiring the energy excess to be curtailed, exported or stored. The limitations of electric energy storage naturally lead to the selection of the well-known form of storing potential energy in reservoirs of reversible hydropower stations, although other technologies such as heat storage are also being used successfully. This paper reviews the storage technologies that are available and may be used on a power system scale and compares their advantages and disadvantages for the integration of fast-growing renewables, such as wind power, with a special focus on the role of pumped hydro storage.
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| 2. |
- Hernando, D., et al.
(författare)
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Heart rate variability during hemodialysis and its relation to hypotension
- 2011
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Ingår i: Computing in Cardiology 2011, CinC 2011. - 9781457706127 ; 38, s. 189-192
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Konferensbidrag (refereegranskat)abstract
- Acute hypotensive episodes are common during dialysis sessions, and represent a serious problem. Spectral analysis of heart rate variability (HRV) and barorrefle x sensitivity (BRS) is performed to study the behaviour of the autonomic nervous system (ANS) during the hemodialysis. The ratio between the low frequency (LF) and high frequency (HF) power of HRV, as well as BRS in the HF band, are significantly different in patients being prone and resistant to hypotension (p<0.001 and p<0.05, respectively). Moreover, a very low frequency (VLF) modulation visible in HRV, blood pressure and the series of rotation angles of the heart's electrical axis have been studied. It turns out that the VLF component is more pronounced and with higher coherence in prone patients (p<0.05), suggesting a possible relation with altered or imbalanced ANS regulation.
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| 3. |
- Ribera, J., et al.
(författare)
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Increased nitric oxide production in lymphatic endothelial cells causes impairment of lymphatic drainage in cirrhotic rats
- 2013
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Ingår i: Gut. - : BMJ. - 0017-5749 .- 1468-3288. ; 62:1, s. 138-145
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Tidskriftsartikel (refereegranskat)abstract
- Background and aim: The lymphatic network plays a major role in maintaining tissue fluid homoeostasis. Therefore several pathological conditions associated with oedema formation result in deficient lymphatic function. However, the role of the lymphatic system in the pathogenesis of ascites and oedema formation in cirrhosis has not been fully clarified. The aim of this study was to investigate whether the inability of the lymphatic system to drain tissue exudate contributes to the oedema observed in cirrhosis. Methods: Cirrhosis was induced in rats by CCl4 inhalation. Lymphatic drainage was evaluated using fluorescent lymphangiography. Expression of endothelial nitric oxide synthase (eNOS) was measured in primary lymphatic endothelial cells (LyECs). Inhibition of eNOS activity in cirrhotic rats with ascites (CH) was carried out by L-N G-methyl-L-arginine (L-NMMA) treatment (0.5 mg/kg/day). Results: The (CH) rats had impaired lymphatic drainage in the splanchnic and peripheral regions compared with the control (CT) rats. LyECs isolated from the CH rats showed a significant increase in eNOS and nitric oxide (NO) production. In addition, the lymphatic vessels of the CH rats showed a significant reduction in smooth muscle cell (SMC) coverage compared with the CT rats. CH rats treated with L-NMMA for 7 days showed a significant improvement in lymphatic drainage and a significant reduction in ascites volume, which were associated with increased plasma volume. This beneficial effect of L-NMMA inhibition was also associated with a significant increase in lymphatic SMC coverage. Conclusions: The upregulation of eNOS in the LyECs of CH rats causes long-term lymphatic remodelling, which is characterised by a loss of SMC lymphatic coverage. The amelioration of this lymphatic abnormality by chronic eNOS inhibition results in improved lymphatic drainage and reduced ascites.
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