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See detailPulp temperature increase during photo-activated disinfection (PAD) of periodontal pockets: an in vitro study.
El Yazami, H.; Zeinoun, T.; Bou Saba, S. et al

in Lasers in medical science (2010)

The capacity of photo-sensitizers, used in combination with laser light to kill micro-organisms has been demonstrated in different studies. Photo-activated disinfection (PAD) has been introduced in ... [more ▼]

The capacity of photo-sensitizers, used in combination with laser light to kill micro-organisms has been demonstrated in different studies. Photo-activated disinfection (PAD) has been introduced in periodontology as an aid for disinfection of periodontal pockets. The aim of this study is to verify the harm for dental vitality of the use of PAD in periodontal pockets. Root canals of 24 freshly extracted human teeth where prepared using profiles up to a size of ISO #50 and filled with thermo-conductor paste. A silicon-based false gum was made in which a periodontal pocket was created and filled with photo-sensitizer phenothiazine chloride (phenothiazine-5-ium, 3.7-bis (dimethylamino)-, chloride). The external root surface was irradiated during 60 s with a 660-nm diode laser (output power: 20 mW; power density: 0.090 W/cm(2); Energy density: 5.46 J/cm(2)) using a periodontal tip with a diameter of 1 mm and a length of 7 mm. Temperatures were recorded inside the root canal using a thermocouple. Measurements were recorded every second, starting at 10 s before lasering, during the irradiation and were continued for 150 s after the end of irradiation, and six measurements were done per tooth. An average temperature increase of 0.48 +/- 0.11 degrees C was recorded. Our results demonstrated that pulp temperature increase was lower than 3 degrees C, which is considered to be harmless for pulp injury. Regarding pulp temperature increase, the use of PAD for disinfection of periodontal pockets can be considered as a safe procedure for dental vitality. [less ▲]

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See detailPulpes de betteraves surpressées complémentées ou aliments complets secs pour les taurillons en croissance-finition.
Thewis, André ULg; Paques, Jean; Leterme, Pascal et al

in Elevages Belges (1985), 39(7), 13-16

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See detailPulsatile glucagon has greater hyperglycaemic, lipolytic and ketogenic effects than continuous hormone delivery in man: effect of age.
Paolisso, G.; Buonocore, S.; Gentile, S. et al

in Diabetologia (1990), 33(5), 272-7

The present study aimed at investigating the hyperglycaemic, lipolytic and ketogenic effects of small doses of glucagon delivered continuously or in a pulsatile manner. The study was performed in eight ... [more ▼]

The present study aimed at investigating the hyperglycaemic, lipolytic and ketogenic effects of small doses of glucagon delivered continuously or in a pulsatile manner. The study was performed in eight healthy young volunteers (24.2 +/- 1.2 years) and in eight healthy aged subjects (69.4 +/- 2.0 years). In all the subjects, endogenous pancreatic hormone secretion was inhibited by somatostatin and only glucagon was replaced. Consequently, the effects of pulsatile and continuous glucagon delivery were studied in conditions of progressive somatostatin-induced insulin deficiency. In both the young and the aged subjects, pulsatile glucagon delivery resulted in increases in plasma glucose, non-esterified fatty acid, glycerol and beta-hydroxybutyrate levels greater than those observed when the same amount of glucagon was delivered in a continuous manner. The net increases in plasma glucose, glycerol and non-esterified fatty acid levels were similar between the young and the aged subjects when glucagon was infused continuously; in contrast, the rise in plasma beta-hydroxybutyrate in the aged was only about half that observed in the young subjects. Surprisingly, when glucagon was infused in a pulsatile manner, the rises in plasma glycerol, non-esterified fatty acid and beta-hydroxybutyrate levels were all significantly smaller in the aged subjects, while no significant differences were observed in the blood glucose responses. We conclude that, in the presence of somatostatin-induced insulin deficiency, pulsatile glucagon exerts greater effects on blood glucose, plasma non-esterified fatty acid, glycerol and beta-hydroxybutyrate levels than its continuous delivery. In the elderly, the lipolytic and ketogenic, but not the hyperglycaemic, responses to pulsatile glucagon are significantly reduced. [less ▲]

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See detailPulsatile hyperglucagonemia fails to increase hepatic glucose production in normal man.
Paolisso, G.; Scheen, André ULg; Luyckx, A. S. et al

in American Journal of Physiology (1987), 252(1 Pt 1), 1-7

To study the metabolic effects of pulsatile glucagon administration, six male volunteers were submitted to a 260-min glucose-controlled glucose intravenous infusion using the Biostator. The endogenous ... [more ▼]

To study the metabolic effects of pulsatile glucagon administration, six male volunteers were submitted to a 260-min glucose-controlled glucose intravenous infusion using the Biostator. The endogenous secretion of the pancreatic hormones was inhibited by somatostatin (100 micrograms X h-1), basal insulin secretion was replaced by a continuous insulin infusion (0.2 mU X kg-1 X min-1), and glucagon was infused intravenously in two conditions at random: either continuously (125 ng X min-1) or intermittently (812.5 ng X min-1, with a switching on/off length of 2/11 min). Blood glucose levels and glucose infusion rate were monitored continuously by the Biostator, and classical methodology using a D-[3-3H]glucose infusion allowed us to study glucose turnover. While basal plasma glucagon levels were similar in both conditions (122 +/- 31 vs. 115 +/- 18 pg X ml-1), they plateaued at 189 +/- 38 pg X ml-1 during continuous infusion and varied between 95 and 501 pg X ml-1 during pulsatile infusion. When compared with continuous administration, pulsatile glucagon infusion initially induced a similar increase in endogenous (hepatic) glucose production and blood glucose, did not prevent the so-called "evanescent" effect of glucagon on blood glucose, and after 3 h tended to reduce rather than increase hepatic glucose production. In conclusion, in vivo pulsatile hyperglucagonemia in normal man fails to increase hepatic glucose production. [less ▲]

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See detailPulsatile insulin delivery has greater metabolic effects than continuous hormone administration in man: importance of pulse frequency.
Paolisso, G.; Scheen, André ULg; Giugliano, D. et al

in Journal of Clinical Endocrinology and Metabolism (1991), 72(3), 607-15

The aim of this study was to see if the greater effect of insulin on hepatic glucose output when insulin is given using 13-min pulses in man remains when the same amount of insulin is delivered using 26 ... [more ▼]

The aim of this study was to see if the greater effect of insulin on hepatic glucose output when insulin is given using 13-min pulses in man remains when the same amount of insulin is delivered using 26-min pulses. The study was performed on nine male healthy volunteers submitted to a 325 min glucose-controlled glucose iv infusion using the Biostator. The endogenous secretion of pancreatic hormones was inhibited by somatostatin. Three experiments were performed in each subject on different days and in random order. In all cases glucagon was replaced (58 ng min-1). The amounts of insulin infused were identical in all instances and were 0.2 mU kg-1 min-1 (continuous), 1.3 mU kg-1 min-1, 2 min on and 11 min off (13-min pulses) or 2.6 mU kg-1 min-1, 2 min on and 24 min off (26-min pulses). Blood glucose levels and glucose infusion rate were monitored continuously by the Biostator, and classic methodology using D-[3-3H] glucose infusion allowed to study glucose turnover. When compared with continuous insulin, 13-min insulin pulses induced a significantly greater inhibition of endogenous glucose production. This effect disappeared when insulin was delivered in 26-min pulses. We conclude that, in man, an adequate pulse frequency is required to allow the appearance of the greater inhibition of pulsatile insulin on endogenous glucose production. [less ▲]

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See detailPulsatile insulin delivery is more efficient than continuous infusion in modulating islet cell function in normal subjects and patients with type 1 diabetes.
Paolisso, G.; Sgambato, S.; Torella, R. et al

in Journal of Clinical Endocrinology and Metabolism (1988), 66(6), 1220-6

The respective modulating effects of continuous and intermittent insulin delivery on pancreatic islet cell function were studied in seven normal men and nine insulin-dependent (type 1) diabetic patients ... [more ▼]

The respective modulating effects of continuous and intermittent insulin delivery on pancreatic islet cell function were studied in seven normal men and nine insulin-dependent (type 1) diabetic patients. In the normal men, saline or continuous (0.8 mU kg-1 min-1) or pulsatile (5.2 mU kg-1 min-1, with a switching on/off length of 2/11 min) human insulin were delivered on different days and in random order. Despite hyperinsulinemia, blood glucose was kept close to its basal value by the glucose clamp technique. The diabetic patients also were infused in random order and on different days with either saline or a smaller amount of insulin delivered continuously (0.15 mU kg-1 min-1) or in a pulsatile manner (0.97 mU kg-1 min-1 for 2 min, followed by 11 min during which no insulin was infused). In all experiments, 5 g arginine were given iv as a bolus dose 30 min before the end of the study, and plasma C-peptide and glucagon levels were determined to assess islet cell function. In the normal men, insulin administration resulted in a significant decline of basal plasma glucagon and C-peptide levels and in a clear-cut decrease in the arginine-induced glucagon response. These effects of insulin were significantly more marked when insulin was delivered in a pulsatile rather than a continuous manner. In the insulin-dependent diabetic patients, the lower dose of insulin infused continuously did not alter the basal or arginine-stimulated glucagon response. In contrast, when the same amount of insulin was delivered intermittently, arginine-induced glucagon release was greatly reduced. Thus, these data support the concept that insulin per se is a potent physiological modulator of islet A- and B-cell function. Furthermore, they suggest that these effects of insulin are reinforced when the hormone is administered in an intermittent manner in an attempt to reproduce the pulsatile physiological release of insulin. [less ▲]

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See detailPulsatile stress in middle-aged patients with Type 1 or Type 2 diabetes compared to nondiabetic controls.
Philips, Jean-Christophe ULg; Marchand, Monique ULg; Scheen, André ULg

in Diabetes Care (2010), 33(11), 2424-2429

AbstractBackground: Arterial pulse pressure (PP) is considered as an independent cardiovascular risk factor. We compared PP during an active orthostatic test in middle-aged patients with type 1 diabetes ... [more ▼]

AbstractBackground: Arterial pulse pressure (PP) is considered as an independent cardiovascular risk factor. We compared PP during an active orthostatic test in middle-aged patients with type 1 diabetes and with type 2 diabetes, and corresponding nondiabetic controls. Methods: 40 patients with type 1 diabetes (mean age 50 years, diabetes duration 23 years, BMI 23.0 kg/m(2)) were compared to 40 non hypertensive patients with type 2 diabetes (respectively, 50 years, 8 years, 29.7 kg/m(2)). Patients taking antihypertensive agents or with renal insufficiency were excluded. All patients were evaluated with a continuous noninvasive arterial blood pressure monitoring (Finapres(R)) in standing (1 min), squatting (1 min) and again standing position (1 min). Patients with type 1 or type 2 diabetes were compared with two groups of 40 age-, sex- and BMI-matched healthy subjects. Results: Patients with type 1 diabetes and patients with type 2 diabetes showed significantly higher PP, heart rate (HR) and PPxHR double product (type 1 : 5263 vs 4121 mmHg/min, p=0.0004; type 2 : 5359 vs 4321 mmHg, p=0.0023) levels than corresponding controls. There were no significant differences between patients with type 1 diabetes and type 2 diabetes regarding PP (59 vs 58 mmHg), HR (89 vs 88/min), and PPxHR product (5263 vs 5359 mmHg/min). Conclusion: Patients with type 1 diabetes have comparable increased levels of peripheral PP, an indirect marker of arterial stiffness, and PPxHR, an index of pulsatile stress, as non-hypertensive patients with type 2 diabetes at similar mean age of 50 years. [less ▲]

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See detailA pulsating auroral X-ray hot spot on Jupiter
Gladstone, G. R.; Waite, J. H.; Grodent, Denis ULg et al

in Nature (2002), 415(6875), 1000-1003

Jupiter's X-ray aurora has been thought to be excited by energetic sulphur and oxygen ions precipitating from the inner magnetosphere into the planet's polar regions(1-3). Here we report high-spatial ... [more ▼]

Jupiter's X-ray aurora has been thought to be excited by energetic sulphur and oxygen ions precipitating from the inner magnetosphere into the planet's polar regions(1-3). Here we report high-spatial-resolution observations that demonstrate that most of Jupiter's northern auroral X-rays come from a 'hot spot' located significantly poleward of the latitudes connected to the inner magnetosphere. The hot spot seems to be fixed in magnetic latitude and longitude and occurs in a region where anomalous infrared(4-7) and ultraviolet(8) emissions have also been observed. We infer from the data that the particles that excite the aurora originate in the outer magnetosphere. The hot spot X-rays pulsate with an approximately 45-min period, a period similar to that reported for high-latitude radio and energetic electron bursts observed by near-Jupiter spacecraft(9,10). These results invalidate the idea that jovian auroral X-ray emissions are mainly excited by steady precipitation of energetic heavy ions from the inner magnetosphere. Instead, the X-rays seem to result from currently unexplained processes in the outer magnetosphere that produce highly localized and highly variable emissions over an extremely wide range of wavelengths. [less ▲]

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See detailPulsating B-type Stars in the Open Cluster NGC 884: Frequencies, Mode Identification, and Asteroseismology
Saesen, S.; Briquet, Maryline ULg; Aerts, C. et al

in Astronomical Journal (2013), 146

Recent progress in the seismic interpretation of field β Cep stars has resulted in improvements of the physical description in the stellar structure and evolution model computations of massive stars ... [more ▼]

Recent progress in the seismic interpretation of field β Cep stars has resulted in improvements of the physical description in the stellar structure and evolution model computations of massive stars. Further asteroseismic constraints can be obtained from studying ensembles of stars in a young open cluster, which all have similar age, distance, and chemical composition. We present an observational asteroseismology study based on the discovery of numerous multi-periodic and mono-periodic B stars in the open cluster NGC 884. We describe a thorough investigation of the pulsational properties of all B-type stars in the cluster. Overall, our detailed frequency analysis resulted in 115 detected frequencies in 65 stars. We found 36 mono-periodic, 16 bi-periodic, 10 tri-periodic, and 2 quadru-periodic stars and one star with nine independent frequencies. We also derived the amplitudes and phases of all detected frequencies in the U, B, V, and I filter, if available. We achieved unambiguous identifications of the mode degree for 12 of the detected frequencies in nine of the pulsators. Imposing the identified degrees and measured frequencies of the radial, dipole, and quadrupole modes of five pulsators led to a seismic cluster age estimate of log (age/yr) = 7.12-7.28 from a comparison with stellar models. Our study is a proof-of-concept for and illustrates the current status of ensemble asteroseismology of a young open cluster. [less ▲]

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See detailA pulsation zoo in the hot subdwarf B star KIC 10139564 observed by Kepler
Baran, A.S.; Reed, M.D.; Stello, D. et al

in Monthly Notices of the Royal Astronomical Society (2012), 424

We present our analyses of 15 months of Kepler data on KIC 10139564. We detected 57 periodicities with a variety of properties not previously observed all together in one pulsating subdwarf B (sdB) star ... [more ▼]

We present our analyses of 15 months of Kepler data on KIC 10139564. We detected 57 periodicities with a variety of properties not previously observed all together in one pulsating subdwarf B (sdB) star. Ten of the periodicities were found in the low-frequency region, and we associate them with nonradial g modes. The other periodicities were found in the high-frequency region, which are likely p modes. We discovered that most of the periodicities are components of multiplets with a common spacing. Assuming that multiplets are caused by rotation, we derive a rotation period of 25.6 ± 1.8 d. The multiplets also allow us to identify the pulsations to an unprecedented extent for this class of pulsator. We also detect l ≥ 2 multiplets, which are sensitive to the pulsation inclination and can constrain limb darkening via geometric cancellation factors. While most periodicities are stable, we detected several regions that show complex patterns. Detailed analyses showed that these regions are complicated by several factors. Two are combination frequencies that originate in the super-Nyquist region and were found to be reflected below the Nyquist frequency. The Fourier peaks are clear in the super-Nyquist region, but the orbital motion of Kepler smears the Nyquist frequency in the barycentric reference frame and this effect is passed on to the sub-Nyquist reflections. Others are likely multiplets but unstable in amplitudes and/or frequencies. The density of periodicities also makes KIC 10139564 challenging to explain using published models. This menagerie of properties should provide tight constraints on structural models, making this sdB star the most promising for applying asteroseismology. To support our photometric analysis, we have obtained spectroscopic radial-velocity measurements of KIC 10139564 using low-resolution spectra in the Balmer-line region. We did not find any radial-velocity variation. We used our high signal-to-noise average spectrum to improve the atmospheric parameters of the sdB star, deriving Teff = 31 859 K and log g = 5.673 dex. Based also on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. [less ▲]

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See detailPulsational analysis of the Herbig Ae star HD 140237
Fumel, Aurélie ULg; Böhm, Torsten

in Communications in Asteroseismology (2008), 157

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See detailPulsational Mode Identification Based on Chromatic Amplitude Behaviour: Recent Results for Rapidly Oscillating Subdwarf B Stars
Randall, S.K.; Fontaine, G.; Brassard, P. et al

in Astronomical Society of the Pacific Conference Series (2012, October), 462

We present recent results from mode identification based on the amplitude-wavelength behaviour for three rapidly pulsating subdwarf B stars: HS 2201+2610, EC 11583–2708 and EC 20338–1925.

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See detailPulsational Mode Identification Based on Chromatic Amplitude Behaviour: Recent Results for Rapidly Oscillating Subdwarf B Stars
Randall, Suzanna K; Fontaine, Gilles; Brassard, Pierre et al

in Astronomical Society of the Pacific Conference Series (2012, September), 462(232),

We present recent results from mode identification based on the amplitude-wavelength behaviour for three rapidly pulsating subdwarf B stars: HS 2201+2610, EC 11583-2708 and EC 20338-1925.

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See detailPulsations du cœur de Scyllium catulus en l’absence d’urée
Fredericq, Léon ULg

in Archives Internationales de Physiologie (1922), XIX

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See detailPulsations in massive stars: effect of the atmosphere on the strange mode pulsations
Godart, Mélanie ULg; Dupret, Marc-Antoine ULg; Noels-Grötsch, Arlette ULg et al

in Proceedings of the International Astronomical Union (2011), 272

Recent space observations with CoRoT and ground-based spectroscopy have shown the presence of different types of pulsations in OB stars. These oscillations could be due to acoustic and gravity modes ... [more ▼]

Recent space observations with CoRoT and ground-based spectroscopy have shown the presence of different types of pulsations in OB stars. These oscillations could be due to acoustic and gravity modes, solar-like oscillations or even other pulsations of large growth rates. We present a first attempt at interpreting the latter as strange modes. [less ▲]

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See detailPulsations in O and B stars
Godart, Mélanie ULg

Conference (2010, June)

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See detailPulsations in white dwarf stars
Fontaine, Gilles; Bergeron, Pierre; Brassard, Pierre et al

in Proceedings of the International Astronomical Union (2014, February), 301

We first present a brief description of the six distinct families of pulsating white dwarfs that are now known. These are all opacity-driven pulsators showing low- to mid-order, low-degree gravity modes ... [more ▼]

We first present a brief description of the six distinct families of pulsating white dwarfs that are now known. These are all opacity-driven pulsators showing low- to mid-order, low-degree gravity modes. We then discuss some recent highlights that have come up in the field of white dwarf asteroseismology. [less ▲]

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See detailPulsations of an Evolved Self-consistently Distorted Star
Ouazzani, Rhita-Maria ULg; Dupret, Marc-Antoine ULg; Roxburgh, I. W. et al

in ASP Conference Proceeding, Vol. 462, 402 (2012, September 01)

A new two-dimensional (2D) non-perturbative method to compute accurate oscillation modes of rapidly rotating stars is presented. The 2D calculations fully take into account the centrifugal distortion of ... [more ▼]

A new two-dimensional (2D) non-perturbative method to compute accurate oscillation modes of rapidly rotating stars is presented. The 2D calculations fully take into account the centrifugal distortion of the star while the non-perturbative method includes the full influence of the Coriolis acceleration, and are used to compute oscillation modes of rapid rotators — high-order p-modes in δ Scuti stars, as well as low-order p- and g-modes in β Cephei stars. We compare the oscillation spectra obtained for centrifugally distorted polytropes with those of Reese et al. (2006), and give the first results for a realistic 2D model of a rapidly rotating 2 M[SUB]&sun;[/SUB] evolved star computed with the method developed by Roxburgh (2006). [less ▲]

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