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Ludovic Berthier - One of the best experts on this subject based on the ideXlab platform.
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Equilibrium equation of State of a hard sphere binary mixture at very large densities using replica exchange Monte-Carlo simulations
Journal of Chemical Physics, 2011Co-Authors: Gerardo Odriozola, Ludovic BerthierAbstract:We use replica exchange Monte-Carlo simulations to measure the equilibrium equation of State of the disordered Fluid State for a binary hard sphere mixture up to very large densities where standard Monte-Carlo simulations do not easily reach thermal equilibrium. For the moderate system sizes we use (up to N=100), we find no sign of a pressure discontinuity near the location of dynamic glass singularities extrapolated using either algebraic or simple exponential divergences, suggesting they do not correspond to genuine thermodynamic glass transitions. Several scenarios are proposed for the fate of the Fluid State in the thermodynamic limit.
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Fluctuation-dissipation relation in a sheared Fluid
Physical Review E : Statistical Nonlinear and Soft Matter Physics, 2001Co-Authors: Jean-louis Barrat, Ludovic BerthierAbstract:In a Fluid out of equilibrium, the fluctuation dissipation theorem (FDT) is usually violated. Using molecular dynamics simulations, we study in detail the relationship between correlation and response functions in a Fluid driven into a stationary non-equilibrium State. Both the high temperature Fluid State and the low temperature glassy State are investigated. In the glassy State, the violation of the FDT is quantitatively identical to the one observed previously in an aging system in the absence of external drive. In the Fluid State, violations of the FDT appear only when the Fluid is driven beyond the linear response regime, and are then similar to those observed in the glassy State. These results are consistent with the picture obtained earlier from theoretical studies of driven mean-field disordered models, confirming the similarity between these models and real glasses.
Karel M.l. Leunissen - One of the best experts on this subject based on the ideXlab platform.
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Fluid State and Blood Pressure Control: No Differences Between APD and CAPD
ASAIO journal (American Society for Artificial Internal Organs : 1992), 2012Co-Authors: Trijntje T. Cnossen, Constantijn J.a.m. Konings, Wouter J. Fagel, Frank M. Van Der Sande, Koos Van Geel, Karel M.l. Leunissen, Jeroen P. KoomanAbstract:The aim of this study was to compare Fluid State, ambulatory blood pressure, and sodiumremoval in automated peritoneal dialysis (APD) and continuous ambulatory peritonealdialysis (CAPD). This observational, cross-sectional study comprised 20 APD and 24 CAPD patients with a mean duration on peritoneal dialysis of 30+/-26 and 21 +/-23 months, respectively. Sixty-four percent of the patients were treated with icodextrin. The methods used were 24 hr dialysate and urine collections, standardized 3.86% glucose peritoneal equilibration test (PET), bioimpedance analysis, and 24 hr ambulatory blood pressure monitoring. Extracellular water (ECW) corrected for body weight was 0.23 6 0.03 L/kg both in APD and CAPD patients. The slope normovolemia value according to Chamney was 0.0 6 0.2 L/kg in APD patients and 0.0 6 0.05 L/kg in CAPD patients (not significant [NS]). Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) were respectively, 132 +/- 25 and 79 +/- 8 mm Hg in APD and 129 +/- 16 and 76 +/- 11 mm Hg in CAPD patients (NS). Sodium concentration in dialysate was respectively, 129.5 +/- 3.5 mmol/L in APD and 132.4 +/- 4.1 mmol/L in CAPD (p= 0.017). Dialysate sodium removal was 80.6 +/- 78.4 mmol/24 hr in APD and 108.7 +/- 96.8 mmol/24 hr in CAPD patients (NS). Natriuresis was respectively, in APD 76.6 +/- 65.5 mmol/24 hr and in CAPD 93.5 +/- 61.7 mmol/24 hr (NS). Total sodium removal was 149.5 +/- 76.6 mmol/24 hr in APD and 198.4 +/- 75.0 mmol/24 hr in CAPD (p= .039). Despite a higher daily sodium removal in CAPD patients, Fluid State and blood pressure were not different between APD and CAPD. In general, volume status and blood pressure appeared to be reasonably controlled in this unselected population.
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Fluid status in capd patients is related to peritoneal transport and residual renal function evidence from a longitudinal study
Nephrology Dialysis Transplantation, 2003Co-Authors: Constantijn J.a.m. Konings, Jeroen P. Kooman, Marc Schonck, Dick G Struijk, Ulrich Gladziwa, S J Hoorntje, Warmold A Van Der Wall Bake, Frank M Van Der Sande, Karel M.l. LeunissenAbstract:Background. Both peritoneal transport characteristics as well as residual renal function are related to outcome in patients treated with continuous ambulatory peritoneal dialysis (CAPD). It has been suggested that part of this relationship might be explained by an effect of both parameters on the Fluid State in CAPD patients or by the relationship between inflammation and peritoneal transport. Methods. In the present study, the relationship between Fluid State [extracellular water (ECW) (sodium bromide); total body water (TBW) (deuterium oxide)] with peritoneal transport characteristics (2.27% glucose dialysateuplasma creatinine [DuP (creat)] ratio), residual renal function (residual glomerular filtration rate [rGFR] by urine collection) and C-reactive protein (CRP) was assessed in 37 CAPD patients in a crosssectional and longitudinal design, with 25 patients completing the study. Results. In the cross-sectional part ECW, corrected for height (ECW:height), was inversely related to rGFR (rs0.40, Ps0.016), whereas during the longitudinal part, DuP[creat] was related to the change in ECW (rs0.40, Ps0.05). Neither DuP[creat] nor rGFR were related to CRP, whereas a significant relationship was observed between ECW:height and CRP (rs0.58, Ps0.0001). Patients were dichotomized according to rGFR (- 2o r) 2m lumin). Despite a higher daily peritoneal glucose prescription (216.3"60.0 vs 156.5"53.0 gu24 h; Ps0.004) and peritoneal ultrafiltration volume (1856"644 vs 658"781 mlu24 h, respectively; Ps0.0001), the patients with a rGFR - 2m lumin showed a higher ECW:height compared with the group with rGFR ) 2m lumin (12.5"3.8 vs 9.2"2.2 lum, respectively; Ps0.003). Results for TBW were comparable. Conclusion. Fluid State was significantly related to peritoneal transport characteristics and rGFR. The larger ECW:height in CAPD patients with a negligible rGFR existed despite a higher peritoneal ultrafiltration volume and higher peritoneal glucose prescription. These findings raise doubts as to whether Fluid State in CAPD patients with a diminished rGFR can be adequately controlled on standard glucose solutions without an additional sodium and Fluid restriction. The preliminary finding of a relationship between CRP and Fluid State might suggest a relationship between overhydration and inflammation.
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Fluid State and blood pressure control in patients treated with long and short haemodialysis.
Nephrology dialysis transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 1999Co-Authors: Krassimir Katzarski, Karel M.l. Leunissen, Bernard Charra, A. J. Luik, J. Nisell, J.c. Divino Filho, J K Leypoldt, Guy Laurent, Jan BergströmAbstract:than the median ECVn in the SH group, without any diVerence in body mass index, but they were nevertheBackground. Patients treated at the haemodialysis (HD) centre in Tassin, France have been reported to less normotensive. The fall in BV was greater in SN than in TN patients, presumably due to a higher have superior survival and blood pressure (BP) control. This control has been ascribed to maintenance of an ultrafiltration rate in SN patients. However, SH patients had a smaller change in BV than SN patients, adequate Fluid State, antihypertensive drugs being required in
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Fluid State and blood pressure control in patients treated with long and short haemodialysis
Nephrology Dialysis Transplantation, 1999Co-Authors: Krassimir Katzarski, Karel M.l. Leunissen, Bernard Charra, A. J. Luik, J. Nisell, J K Leypoldt, Guy Laurent, J Divino C Filho, Jan BergströmAbstract:than the median ECVn in the SH group, without any diVerence in body mass index, but they were nevertheBackground. Patients treated at the haemodialysis (HD) centre in Tassin, France have been reported to less normotensive. The fall in BV was greater in SN than in TN patients, presumably due to a higher have superior survival and blood pressure (BP) control. This control has been ascribed to maintenance of an ultrafiltration rate in SN patients. However, SH patients had a smaller change in BV than SN patients, adequate Fluid State, antihypertensive drugs being required in <5% of the patients, although it could not presumably because their State of overhydration facilitated refilling of BV from the interstitial Fluid. be excluded that a high dose of HD regarding removal of uraemic toxins might also have been of value. Conclusions. Normotension can be achieved independently of the duration and dose ( Kt/V urea) of HD, if Methods. The aim of the study was to assess the Fluid State and BP in normotensive patients on long HD the control of post-dialysis ECV is adequate. However, this is more diYcult to achieve with short than with (8 h) in Tassin (group TN ) using bioimpedance to measure extracellular volume ( ECV ), ultrasound for more prolonged HD during which the ultrafiltration rate is lower, BV changes are smaller and intradialysis determining the inferior vena cava diameter (IVCD), and ‘on-line’ monitoring of the change in blood volume symptoms less frequent. The results in the subgroup of patients with high ECVn at Tassin suggest that (BV ), and to compare them with normotensive (group SN ) and hypertensive (group SH ) patients on short normotension may also be achieved in patients with Fluid overload provided that the dialysis time is long HD (3‐5 h) at centres in Sweden. ECV was normalized ( ECVn) by arbitrarily setting the median ECV (in % enough to ensure more eYcient removal of one or more vasoactive factors that cause or contribute to
Jan Bergström - One of the best experts on this subject based on the ideXlab platform.
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Fluid State and blood pressure control in patients treated with long and short haemodialysis.
Nephrology dialysis transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 1999Co-Authors: Krassimir Katzarski, Karel M.l. Leunissen, Bernard Charra, A. J. Luik, J. Nisell, J.c. Divino Filho, J K Leypoldt, Guy Laurent, Jan BergströmAbstract:than the median ECVn in the SH group, without any diVerence in body mass index, but they were nevertheBackground. Patients treated at the haemodialysis (HD) centre in Tassin, France have been reported to less normotensive. The fall in BV was greater in SN than in TN patients, presumably due to a higher have superior survival and blood pressure (BP) control. This control has been ascribed to maintenance of an ultrafiltration rate in SN patients. However, SH patients had a smaller change in BV than SN patients, adequate Fluid State, antihypertensive drugs being required in
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Fluid State and blood pressure control in patients treated with long and short haemodialysis
Nephrology Dialysis Transplantation, 1999Co-Authors: Krassimir Katzarski, Karel M.l. Leunissen, Bernard Charra, A. J. Luik, J. Nisell, J K Leypoldt, Guy Laurent, J Divino C Filho, Jan BergströmAbstract:than the median ECVn in the SH group, without any diVerence in body mass index, but they were nevertheBackground. Patients treated at the haemodialysis (HD) centre in Tassin, France have been reported to less normotensive. The fall in BV was greater in SN than in TN patients, presumably due to a higher have superior survival and blood pressure (BP) control. This control has been ascribed to maintenance of an ultrafiltration rate in SN patients. However, SH patients had a smaller change in BV than SN patients, adequate Fluid State, antihypertensive drugs being required in <5% of the patients, although it could not presumably because their State of overhydration facilitated refilling of BV from the interstitial Fluid. be excluded that a high dose of HD regarding removal of uraemic toxins might also have been of value. Conclusions. Normotension can be achieved independently of the duration and dose ( Kt/V urea) of HD, if Methods. The aim of the study was to assess the Fluid State and BP in normotensive patients on long HD the control of post-dialysis ECV is adequate. However, this is more diYcult to achieve with short than with (8 h) in Tassin (group TN ) using bioimpedance to measure extracellular volume ( ECV ), ultrasound for more prolonged HD during which the ultrafiltration rate is lower, BV changes are smaller and intradialysis determining the inferior vena cava diameter (IVCD), and ‘on-line’ monitoring of the change in blood volume symptoms less frequent. The results in the subgroup of patients with high ECVn at Tassin suggest that (BV ), and to compare them with normotensive (group SN ) and hypertensive (group SH ) patients on short normotension may also be achieved in patients with Fluid overload provided that the dialysis time is long HD (3‐5 h) at centres in Sweden. ECV was normalized ( ECVn) by arbitrarily setting the median ECV (in % enough to ensure more eYcient removal of one or more vasoactive factors that cause or contribute to
Krassimir Katzarski - One of the best experts on this subject based on the ideXlab platform.
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Fluid State and blood pressure control in patients treated with long and short haemodialysis.
Nephrology dialysis transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 1999Co-Authors: Krassimir Katzarski, Karel M.l. Leunissen, Bernard Charra, A. J. Luik, J. Nisell, J.c. Divino Filho, J K Leypoldt, Guy Laurent, Jan BergströmAbstract:than the median ECVn in the SH group, without any diVerence in body mass index, but they were nevertheBackground. Patients treated at the haemodialysis (HD) centre in Tassin, France have been reported to less normotensive. The fall in BV was greater in SN than in TN patients, presumably due to a higher have superior survival and blood pressure (BP) control. This control has been ascribed to maintenance of an ultrafiltration rate in SN patients. However, SH patients had a smaller change in BV than SN patients, adequate Fluid State, antihypertensive drugs being required in
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Fluid State and blood pressure control in patients treated with long and short haemodialysis
Nephrology Dialysis Transplantation, 1999Co-Authors: Krassimir Katzarski, Karel M.l. Leunissen, Bernard Charra, A. J. Luik, J. Nisell, J K Leypoldt, Guy Laurent, J Divino C Filho, Jan BergströmAbstract:than the median ECVn in the SH group, without any diVerence in body mass index, but they were nevertheBackground. Patients treated at the haemodialysis (HD) centre in Tassin, France have been reported to less normotensive. The fall in BV was greater in SN than in TN patients, presumably due to a higher have superior survival and blood pressure (BP) control. This control has been ascribed to maintenance of an ultrafiltration rate in SN patients. However, SH patients had a smaller change in BV than SN patients, adequate Fluid State, antihypertensive drugs being required in <5% of the patients, although it could not presumably because their State of overhydration facilitated refilling of BV from the interstitial Fluid. be excluded that a high dose of HD regarding removal of uraemic toxins might also have been of value. Conclusions. Normotension can be achieved independently of the duration and dose ( Kt/V urea) of HD, if Methods. The aim of the study was to assess the Fluid State and BP in normotensive patients on long HD the control of post-dialysis ECV is adequate. However, this is more diYcult to achieve with short than with (8 h) in Tassin (group TN ) using bioimpedance to measure extracellular volume ( ECV ), ultrasound for more prolonged HD during which the ultrafiltration rate is lower, BV changes are smaller and intradialysis determining the inferior vena cava diameter (IVCD), and ‘on-line’ monitoring of the change in blood volume symptoms less frequent. The results in the subgroup of patients with high ECVn at Tassin suggest that (BV ), and to compare them with normotensive (group SN ) and hypertensive (group SH ) patients on short normotension may also be achieved in patients with Fluid overload provided that the dialysis time is long HD (3‐5 h) at centres in Sweden. ECV was normalized ( ECVn) by arbitrarily setting the median ECV (in % enough to ensure more eYcient removal of one or more vasoactive factors that cause or contribute to
R. J. D. Miller - One of the best experts on this subject based on the ideXlab platform.
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Myoglobin dynamics: evidence for a hybrid solid/Fluid State of matter
Journal of Luminescence, 2001Co-Authors: Jennifer P. Ogilvie, Michael R. Armstrong, Marie Plazanet, Gami Dadusc, R. J. D. MillerAbstract:Abstract The dynamics of carboxy-myoglobin (MbCO) in water are studied from photodissociation of the ligand to bimolecular recombination over 12 decades in time to fully characterize the protein functions. Heterodyne-detected transient grating spectroscopy is used to resolve the dynamics of the protein from 10 ns to a few ms and provides a direct observation of the ligand escape. The process is well described by a bi-exponential function with decay rates of 50 and 725 ns at 20°C, suggesting that ligand escape occurs via a well defined pathway. Transient absorption in the Q-band (550–630 nm) also reveals the sensitivity of the electronic transition to the ligand motions. The dynamic range is extended by 10 6 through femtosecond coherence spectroscopy with 7 fs pulses to enable the observation of vibrational modes of energies >1500 cm −1 . The power spectrum is calculated by singular value decomposition and vibrational modes involved in the photodissociation are directly observed. The picture that is emerging is that proteins couple solid-like domains to Fluid regions to facilitate functions and transport of ligands in and out of the protein to the active site.